1.Define productivity. 2.Identify the key factors which affect productivity levels. 3.How will better material utilisation improve productivity? 4.What is meant by job enrichment? 5.Recall the six basic steps of method study. 6.Write down the symbols used in constructing a flow process chart. 7.Why is the identification of ‘key’ operations necessary when we are undertaking critical examination? 8.Why is it vital to maintain an interest in the ongoing performance of a new system of work? 9.Why should job times ideally be established after methods have been specified? 10.Write down the principles which underpin a well-designed financial incentive scheme.
Productivity Methods and Measurements
In this unit we will concentrate on methods for improving productivity. In particular we will consider one of the key resources of an organisation, its workforce. In this unit, we will look at issues which impinge upon effective workforce management from an operations management perspective. We will examine Japanese and Western organisations to learn about factors which lead to employee motivation and commercial success. We will identify the inputs of resources which are utilised in manufacturing, administrative and service systems and we will consider the concepts of productivity measurement and improvement. Finally we will introduce important productivity-raising techniques used by many operations managers: method study and work measurement.
By the end of this unit, you should be able to:
• understand workforce management practises in Japanese and Western organisations
• identify resources used by organisations
• define productivity
• choose appropriate productivity raising approaches
• understand the analytical problem-solving methodology of method study
• use the techniques of flow process charting and multiple activity charting
• critically examine key aspects of a job with a view to overall improvements
• use several creative thinking techniques in your search for change
• pull together all the varied aspects present in new method proposals
• appreciate the complexities involved in the installation of a new method
• understand the necessity to maintain the new system so that we continue to attain the correct levels of productivity
• understand how work measurement is undertaken
• explain the significance of the standard time value and the uses of time values in payment schemes and in capacity planning.
SECTION 1: Workforce Management Perspectives
In this section we will look at European and Japanese approaches to management and the deployment of human resources.
1.1 European perspectives
In their research undertaken across Europe, Lessem and Neubauer (1994) examined the approaches and styles adopted by managers faced with changing situations and differing cultural mixes. They identified four levels of managerial expertise:
• attribute-based managers. These individual managers endeavour to cope with both behavioural and attitudinal changes which are occurring across different organisations and countries.
• model-based managers. These senior managers need to handle complex institutional structures and diverse organisational concepts across international frontiers.
• idea-based managers. This group of managers develop economic and philosophical ideas about the recovery or growth of a company or a whole industry from a complex set of factors.
• image-based managers. These managers seek to influence the external environment ¬ where the customer or client is ¬ either regionally, nationally or internationally.
Within this framework it is possible to see the integral nature of operations management to business enterprise and execution. We will see the problems associated with change. Where productivity needs to be raised, changes in work practices and pay systems may need to be made and wholesale restructuring may become essential. Our concerns from an operations management perspective centrearound the first three of these managerial categories in this unit. We cover the image-based manager at the interface with marketing in the units on product design and distribution.
As many of the modern operational management practices have been taken on and fine-tuned to perfection by Japanese business, we look first at the Japanese perspective.
1.2 Japanese perspectives
Japanese economic competitiveness has been founded upon four major factors:
1. Complex systems are managed in simple ways.
This helps to minimise the conflicts which exist between human needs and the requirements of the organisation. Having a harmonious workplace is a vital feature of the Japanese work ethic. The company makes a total commitment to the employee and expects loyalty. It shares knowledge with them and appreciates their ideas and contribution. The employee is involved in the design and operation of the process.
2. There is a clear focus on the human resources available.
This is demonstrated through the drive for quality, the consideration given to employee needs, the emphasis upon teamwork and co-operation and the careful selection of compatible people to fit into the system.
3. The need for high productivity, high quality and precise completion dates is emphasised.
There is a commitment to continuous improvement in the drive to reduce costs.
4. Consensual decision-making is designed into each job (the `ringi’ system).
This is based on a bottom-up strategy, which uses the greater number of people, rather than the top-down approach, which uses only one or two senior figures to make the decisions. Where possible, decisions are made as low down the organisational structure as possible as a result of this empowerment process.
There is a need for vision to define where the business is heading, and to clearly communicate intentions and objectives to the employees. The Japanese value the importance of a cohesive system in which everything fits well. One of the problems which Western businesses have experienced is that it is difficult to attach part of the Japanese approach to a typical European company. For example, quality circles may operate nominally but produce few results due to the fears possessed by the staff. The JIT system needs a chain of suppliers who are similarly interested in quality, reliability and timing in order to minimise stock costs.
A cohesive system correlates the talents of the employees with the organisational objectives and creates an internal environment which allows the development of greater potential.
In order to achieve this, it is necessary for:
• each member of staff to commit themselves to self-development
• each manager to coach his or her staff to maximise his or her potential
• theorganisational climate to stimulate the learning process.
This structure is illustrated in diagrammatic form in Figure 1.
Figure 1: Japanese management approach
The company is seen as a learning organisation, with career development, job performance and skills development opportunities. Appraisal schemes exist to check that all is well, to review the past and set targets for the future It is the responsibility of management to provide an appropriate environment in which learning can occur. Well-designed jobs underpinned by proven procedures lead to job satisfaction, a motivated workforce and high productivity levels.
With all this in mind let’s have a closer look at what productivity is, and some of the techniques which can be used to raise it.
In this section we first looked at European approaches to management and the deployment of human resources. We then looked at the Japanese approach.
SECTION 2: Productivity
In this section, we will define and discuss productivity, how it is measured and techniques for increasing it.
Productivity is the ratio between output and input. We can also define it as the quantitative relationship between what is produced and the resources used. Thus:
Productivity is therefore different from production, which is concerned with volume. It is possible to increase the volume of production and yet decrease productivity.
HOW PRODUCTIVITY IS MEASURED
In practice, productivity is often expressed in terms of different indices, for example:
Labour index = output per employee hour
Material index = output per ton of raw material (or some other measure)
Capital index = output per £1,000 of capital invested.
The basic reasons for the calculation of specific indices are:
• comparison purposes, to observe trends
• in some situations certain indices are of overriding importance, for example, material utilisation would probably be of paramount importance in the diamond-cutting trade.
HOW PRODUCTIVITY CAN BE INCREASED
Productivity can be increased by getting:
• more output from the same input
• same output from less input
• more output from less input
• considerably more output from a little more input
• slightly less output from considerably less input.
Let’s consider some examples. A farmer uses better seed and fertiliser to increase corn yield from the same piece of land; costs rise but he or she gets proportionately more return. A tailor finds he or she is able to cut out 11 blouses from a roll of cloth instead of 10 using a different method.
Other definitions include:
• `A measure of the efficiency with which resources are converted into the products and services that people need.’
• `Output per employee hour, quality considered.’
• `The continual improvement of the efficiency of an organisation which results in increasingly efficient use of the materials, labour, plant and machinery available.’
Go To Activity One
Go To Activity Two
Productivity concerns inputs. The inputs include a variety of resources: money, materials, equipment and people. Figure 2 illustrates the flow of input into a productive unit and the flow of output, the product or service.
Figure 2: Diagram of the productive unit
FACTORS AFFECTING PRODUCTIVITY
The factors affecting productivity, can be grouped into three main categories:
• Government policies: which play an important part in establishing the conditions under which firms operate. Financial policies affect interest rates and therefore the cost of capital and its availability. Tariffs and import quotas are factors which have to be considered prior to investment decisions being taken.
• Geographical factors: which affect the availability of indigenous sources of raw materials or fuel. Transportation charges inevitably increases cost.
• Managerial skill: which in the final analysis is responsible for the efficient use of all the resources in its control. The degree, or absence, of management skill will greatly affect the productivity of the enterprise through its output.
2.3 Productivity-raising techniques
There are a variety of techniques we can use to increase productivity.
• Work study: one of the main productivity-increasing techniques designed to help management to make better use of all resources. It pays close detailed attention to actual productive operations. In many organisations the discipline is called `management services’ or `organisation and methods’.
• Capital investment: productivity can be raised by the injection of capital to purchase new equipment and modernise old. To be effective, capital is often required on a large scale and the results are long term.
• Simplification and standardisation: often a matter of basic design coupled with a determination by management to reduce the number and variety of products and equipment. Specification and design can often be simplified.
• Quality standards: sometimes unrealistic, with designers and engineers demanding a quality which is far higher than the work requires. The specification of an appropriate quality standard can reduce unnecessarily high costs.
• Material utilisation: productivity can be raised by improved control of materials, with regard to purchasing, storage, usage, issuing and transportation, simplification of product design can also affect material costs.
• Use of plant and equipment: careful and detailed planning by management is essential to ensure maximum utilisation of expensive plant and equipment. The design and implementation of effective maintenance systems are a particular help in raising productivity.
• Research and development: essentially a long-term way of raising productivity. Existing techniques of production are improved and new processes developed, often at considerable capital cost. The results are frequently long term.
• Use of manpower: In many situations manpower represents a substantial element of cost. Effective use of manpower is only achievable through good planning based on accurate data, and adequate supervisory control. Many of the above techniques will also have implications for the use of manpower.
Go To Activity Three
In this section we began by defining productivity, how it is measured and, in broad terms, how it can be increased. We also examined factors affecting it and we ended with a review of techniques for raising productivity.
SECTION 3: Job Design
In this section we will discuss job design and the effects of new technology in the workplace. We will look at strategies for coping with changes and problems arising within the working environment.
3.1 Nature of job design
The careful identification and arrangement of tasks which together build up into a portion of work is called job design. For this to be a success in terms of productivity, we must add a further dimension. We need to match the job itself and the individual charged with the responsibility of performing it. The closer the match, the greater will be the motivation of the operator to achieve the objectives laid down in terms of quality and output.
One of the increasingly important factors since the Industrial Revolution has been the degree to which machinery and technology lays down rigid criteria for the performance of at least part of many operations. The move away from craft work into mass production factory systems increasingly drew in the skills of machine design engineers, electrical engineers and, latterly, computer programmers as technology advanced. Some of the earliest attempts of formal job design were undertaken in the late 1800s by F W Taylor and F B Gilbreth. The approach they pioneered, that of breaking down existing jobs into components called elements, and of composing new job routines by building up these elements, is still the method largely used today. The approach led to job specialisation, with a narrow range of component parts, high levels of repetition, minimum training needs and expected high productivity attainment.
The introduction of computer-controlled machine tools and robots into the workplace has resulted in a steady decline in high-volume, routine, monotonous jobs with little stimulus for operator motivation. Administrative jobs within both the manufacturing areas and the office block have moved in the same direction. Routine clerical procedures, job cards, clock cards, worksheets, bonus calculations and quality control sheets have disappeared with the spreading of computer terminals throughout organisations. The result is that those staff who remain tend to have been pushed to the margins of the process. In the manufacturing section they look after the input supply of materials or components, internal storage arrangements and the despatch or distribution of the product. Wider control processes accessed from a computer terminal have been assigned to various support services, for example, health and safety or security. Administratively, staff concentrate much more time now on public relations, customer complaints and quality assurance certification systems, rather than routine clerical work.
The fast-changing nature of jobs has presented new types of problem to those involved in job design. Method-study specialists, for example, have not had to contend so much with the effects of physical fatigue in the performance of work but have been faced with combating the extremes of mental fatigue, or complete boredom, in some cases.
Go To Activity Four 3.3 Strategies
A number of strategies can be introduced into the design of jobs which are aimed at overcoming the sort of issues we have just been considering. These include job rotation, job enlargement and job enrichment.
JOB ROTATION SCHEDULES
Staff move to different kinds of work either at set intervals or at the discretion of their supervisor. In a supermarket, for example, a full-time member of staff might expect to spend a third of each 7.5 hour working day in each of the following sections: cash point, pricing labels and stock control, loading shelves. Rotation of this kind increases interest, provides variety, widens skills and reduces boredom. From the perspective of management, a more flexible workforce is established, there will be less chance of claims arising for medical conditions such as Repetitive Strain Injury (RSI) and, hopefully, labour turnover will be reduced. Staff may develop an awareness of the value of the internal customer concepts advocated by the TQM approach, and feel a more significant member of a quality circle, as a result of rotation.
Problems can arise in a job rotation arrangement when successive types of work are not at the same skill level. Staff may be under- or overstretched for at least part of the time.
Appropriate principles can be introduced into the job design process. The aim is to provide the operator with a larger, more significant role relative to the accomplishment of the whole job. The range of tasks given are generally pitched at the same level. This horizontal expansion can be augmented by some vertical dimensioning, for instance in the area of quality checking. An example would be the university lecturer whose original job description centred upon a balance between teaching and research. The work contract was redesigned to include income-generating consultancy, and the quality aspects of new degree proposals.
This is the most comprehensive of the approaches to job design. Much greater emphasis is put upon vertical expansion of work and upon empowering the operator. Self-directed and self-managed teams can be set up and given almost complete responsibility for the accomplishment of the task. Sometimes external liaison with suppliers, customers and legal authorities is undertaken. The work may, on the other hand, be undertaken by one member of staff who has received sufficient training to be able to handle it. An example could be a telephone enquiry about planning permission requirements received at the town council offices. The member of staff interrogates the expert system and gives the caller a preliminary opinion. The staff member then follows this through with a more extensive search, discusses the matter with colleagues, and then word processes and despatches the final decision to the enquirer. If further correspondence ensues, then the member of staff concerned tends to handle it.
In summary, therefore, job enlargement involves a variety of skills, meaningful overall objectives, a degree of autonomy and feedback.
The restructuring of jobs has often led to the need for organisational redesign. When jobs begin to span boundaries, managerial control and accountability becomes more complex. Organisations, or specific divisions within them, may be redesigned along matrix principles rather than the more traditional functional or line and staff structures.
With regard to staff motivation, Herzberg’s and Maslow’s theories of motivation contend that the kind of points we have been discussing will have little effect unless the basic needs of the staff are being met. This indicates the need for good organisational policies, practices and systems to be in place.
Needs hierarchy theory suggests that workers have a complex set of strong needs which can be placed in a hierarchy and which are underpinned by the following assumptions:
• a satisfied need does not in itself act as a motivator. The fact that another need soon emerges, which itself needs satisfying, causes the drive.
• several needs affect the behaviour of a worker at any one time.
• lower level needs in the hierarchy (which are physiological and security based) must be satisfied first.
• there is an increasingly wide range of options available to satisfy higher-level needs (affiliation, esteem and self-actualisation).
Later theorists have adapted the work of Maslow. Clayton Alderfer (1972) suggests that there are three sets of basic needs:
• existence needs (material needs which are satisfied by food, air, water, pay)
• relatedness needs (interpersonal relationships)
• growth needs (personal development opportunities). The implications of these theories to the job designer are obvious, assuming that they model the behavioural realities of the workplace in motivational terms.
In this section we looked at the features of job design and the problems facing those involved with it as a result of changes in the modern workplace. We considered some of the possible strategies for resolving such problems.
SECTION 4: Problem Solving using the Method Study Approach
Job design and redesign often surface as a result of problems in the workplace. As a student of operations management, therefore, you need to look at the question of problem solving using the well-proven approach known asmethod study. We will look at each step in the basic six-step method study procedure in turn and highlight related considerations and techniques
As we saw in Unit 1, the origins of modern work study lies in the era of `scientific management’, which was beginning to gather momentum about a century ago. The names of F W Taylor and F B Gilbreth are always associated with the development of the foundation techniques used in work study. Although many advances have been made since their time through the work of others, or through technological advance, the underlying principles and methodological approach are of great value to the operations manager in job design, problem solving, the setting of standards and motivation of staff.
4.1 Objectives of method study
The objectives of undertaking method study are to:
• eliminate unnecessary work
• reduce unnecessary fatigue
• improve processes and procedures
• improve layouts and methods of materials handling
• make better use of manpower, machines and materials
• improve working conditions
• improve and simplify design
• improve and maintain quality.
These objectives are achieved by collecting the facts, exposing them to searching critical examination and redeveloping methods. Method study is not a science but a systematic and creative way of thinking. It provides a channel for the inventive ability which exists in all organisations. The method study practitioner is not necessarily the inventor or originator of new methods but rather an evaluator of ideas.
The classical analytical problem-solving methodology includes the following steps:
• search for alternatives
• cause acceptance
• follow up.
The operations manager who chooses to use this methodology will probably find it helpful to concentrate thinking within the guidelines of the well-proven six step approach of method study. Generations of problem solvers have used the six steps and learned the order by using the mnemonic SREDIM, which stands for Select, Record, Examine, Develop, Install and Maintain.
We refer throughout this unit to definitions included in the document produced by the British Standards Institute, entitled `Terms used in work study and organisation and methods’, BS3138, 1979. (Note: BS stands for British Standards Institute, 3138 identifies the document.)
Here are two important definitions with their reference numbers:
• 10001 Work Study ¬ the systematic examination of activities in order to improve the effective use of human and other material resources
• 10003 Method Study ¬ the systematic recording and critical examination of ways of doing things in order to make improvements.
In the following pages we will generally only refer to the definition reference number rather than repeating the document number. There is a definition for many factors in the methodology. They are shown in italics
Method study is:
• diagnostic (it determines faults}
• remedial (it improves situations)
• constructive (it sets standards for control).
4.3 The basic procedure
The six-step approach, SREDIM, is:
• Select – the work to be studied
• Record – all the relevant facts about the present method by direct observation
• Examine – those facts critically and in ordered sequence, using the techniques best suited to the purpose
• Develop – the most practical, economic and effective method, having due regard to all contingent circumstances
• Install – that method as standard practice
• Maintain – that standard practice by regular routine checks.
You should learn these six steps.
Method study seeks to achieve:
• equal results at lower cost
• better results at same cost
• better results at lower cost.
The relationship between method study and the associated technique of work measurement is shown in Figure 3 (over page). The final result is higher productivity.
Figure 3: Relationship between method study and work measurement
Go To Activity Five
4.4 Step 1: Selecting the work to be studied
31003: The process of choosing by systematic means, a specific problem to be solved, or an area of work to be studied.
This is the initial step in the basic method study procedure. Often there is opportunity for the work study practitioner to make decisions on which areas of work are likely to be the most rewarding, and to establish priorities for study work.
In making such decisions there are three aspects which must be taken into account:
• economic considerations
• technical considerations
• human reactions.
These are usually the most important, as method study is concerned with economic use of resources. The need for improvement in a process is not always apparent. It is often the case that existing methods are defective but are accepted simply because they have been long practised and unchallenged. Some jobs, like those with a short-run expectancy and no repeat orders in hand, are economically unattractive, even though methods are poor.
Jobs requiring methods investigation are indicated when they display features like the following:
• the job is a production bottleneck
• there are movements of material over long distances between processes
• lack of balance in labour-intensive teamwork jobs
• highly repetitive, long-running orders have never been method studied before q poor production planning, which results in too much work-in-progress
• a high reject rate
• wide variations in quality of work
• high labour turnover
• excessive amounts of overtime being worked
• unsafe working practices
• very high relaxation allowances required
• inefficient use of resources (manpower, materials, machines, space)
• improvements envisaged by the operator by means of a suggestion scheme.
There are two areas to be taken into account when selecting work for study:
• The skill, competence and training of the work-study practitioner to handle this particular assignment.
• The technical limitations of the process itself must be borne in mind so that new methods are not `invented’ which will prove unworkable. Specialist technical expertise must often, therefore, be sought, so that investigations are not commenced which have to be abandoned for technical reasons at a later date, with no beneficial outcome.
It is difficult to predict human reactions to work study. There are sometimes strong mental and emotional reactions to investigations into a particular area of work. Very often these feelings lie dormant until changes are formally proposed. Adequate communication is the most helpful way of reducing tensions and suspicions.
Knowledge of local personnel and conditions, together with early consultation with management, trade unions and operators, all help to take human reactions into account at the select stage.
Work study cannot be imposed on operators. Nor can it effectively succeed without the co-operation of supervisors, who are usually the first link between the practitioner and operator at the commencement of work study.
4.5 Step 2: Recording the facts
After selecting the work to be studied, it is essential to record all the relevant facts of the existing method. The success of the whole procedure will probably depend on the accuracy with which the facts are recorded.
There are many ways of recording the detail contained in a particular sequence of events. One method is the detailed long-hand account, which is tedious both to produce and comprehend. Consequently a wide range of recording techniques have been developed to cater for the recording of all types of work. These can be broadly classified into:
• charts (for process and time records)
• diagrams and models (for path of movement records)
• written descriptions
• photographic and video techniques.
The graphical or pictorial presentation of data is found to be invaluable to the methods investigator who must study situations, which are often complex, in a systematic way. At a later stage in the investigation it will again be necessary to explain the proposals and these charts and diagrams will be very helpful.
Some recording techniques are easier and cheaper to apply than others in a given situation. Obviously the skilled investigator selects the right tools for the job like any craftsman does. A checklist of relevant data is often found helpful in ensuring that essential background details are not overlooked.
A TYPICAL CHECKLIST
• product/operation or service
• investigation proposer
• reason for the proposal
• suggested limits of the investigation
• job particulars:
– Output per week?
– What percentage is this of departmental output ?
– How long will the job last?
– Will output levels increase or decrease ?
– Staffing levels: direct/indirect/administration?
– Job evaluation grades and pay levels?
– What are the individual operative output levels?
– How is payment made?
(team work, piece work, premium bonus, basic pay etc.)?
– When were any existing targets or standards set?
– Has the job any unpleasant or injurious features?
– What equipment is used?
– What equipment efficiencies are achieved?
– Is the existing amount of space adequate or excessive?
– Which pieces of equipment would be difficult to relocate?
– Are aisles clearly defined?
• Product or service
– Are there frequent changes calling for design modifications?
– Can the product be modified for easy manufacture?
– Can the service be simplified?
– What quality is specified?
– When and how is the product inspected?
• Savings potential
– through reduction in the `work content’ of the product or service
– through better equipment efficiency and utilisation
– through better use of labour
– through reduced scrap or wasted time.
In this unit we shall be concentrating on developing skills in two of the work study recording techniques which are of major interest to operations management staff:
• flow process charting
• multiple activity charting.
You have already met these techniques in Unit 6. Additional techniques can be found in the books listed as recommended reading at the end of the unit.
PROCESS CHART SYMBOLS
32003: Symbols used for recording the nature of events.
The five symbols in most common use today were developed by the American Society of Mechanical Engineers (ASME) in 1947.
Indicates the main steps in a process, method or procedure.
Usually the part, material or product concerned is modified or changed during the operation. An operation always takes the material, component or service a step towards completion.
Examples: machining an article; a chemical reaction; screwing a nut to a bolt; unpacking a parcel; tying a knot.
Indicates an inspection for quality and/or a check for quantity.
An inspection does not take the material, component or service further towards completion. It simply verifies that specified operations have been done correctly.
Examples: testing yarn; counting rows; checking a part with micrometer; using a spirit level against a wall.
Indicates the movement of workers, materials or equipment from place to place.
Examples: material carried to bench; walk to stores; part moved by conveyor.
4. Delay (or temporary storage)
Indicates a delay in the sequence of events.
For example, work or worker waiting between consecutive processes, or any object laid aside temporarily without record until required.
Examples: material awaiting hoist; operative awaiting material; castings awaiting machining.
Indicates a controlled storage in which material is received into or issued from a store under some form of authorisation, or an item is retained for reference purposes.
Examples: document in filing cabinet; tools in stores awaiting issue; goods in warehouse.
Note: the difference between and is that a formal requisition or chit is usually required to get work out of storage, but not out of temporary storage. Delays of more than 24 hours are usually classified as storages.
When two activities are performed simultaneously, for example, when an inspection is carried out whilst an operation is being performed, then one symbol can be superimposed on another. The activity which seems to be the most important is shown as the outer symbol.
The way the symbols are used on different types of process chart can be seen in Figure 4.
Symbol Process chart
Outline Flow process chart Two handed
Main type Material type
Operation Operation Operation Operation
— Transportation Transportation Transportation
Inspection Inspection Inspection —
— — Storage Hold
— Delay Delay Delay
Figure 4: Flow process and process chart symbols
FLOW PROCESS CHARTS 32004:
A process chart setting out the sequence of the flow of a product or a procedure by recording all events under review using the appropriate process chart symbols.
An outline process chart does not show what occurs between operations and inspections. The flow process chart, however, does cover this part of the procedure by use of the additional symbols, transport, storage and delay.
The flow process chart enables systematic analysis to be made of all the events in a process, with the consequent elimination, reduction or combination of operations, inspections, transports, delays and storages.
Two examples of flow process charts follow: study them carefully.
The first is buying a train ticket (Figure 6); the second records unloading goods in a warehouse (Activity 6, Figure 7).
Note the conventions for dealing with repeat situations and numbering up in symbol series, as shown in Figure 5. Note also the use of standard times. This is the time that it actually takes to do a task and an `allowance’ as the operator cannot work at exactly the same pace throughout the working day. The standard time can be measured in minutes (SMs) or hours (SHrs).
We look at this in more detail in the next section.
Figure 5: Convention for repeat situations in a flow process chart
This part of a flow process chart shows the repeat convention bracket.
Activities operation 8 and transport 1 occur four times in the work situation charted. The number used in the repeat line is always one less than the total as the first occasion is plotted on the chart, (hence the (n¬1) rule).
Figure 6: Buying a train ticket flow process chart
Go To Activity Six
Go To Activity Seven
MULTIPLE ACTIVITY CHARTS
32017: A chart on which the activities of more than one subject (worker, equipment or material) are each recorded on a common time-scale to show their interrelationship.
In a situation where there are two or more related activities being carried out in close association with one another, requiring a balance to be achieved, multiple activity charts are the most suitable recording technique. Each separate group of activities is shown in bar form alongside all other related activities against a common time-scale.
There are a series of steps you go through to construct a multiple activity chart:
• Prepare a flow process chart for each operative or machine involved in the process.
• Activities recorded must then be grouped into convenient `elements’ for time study.
• Sufficient time study observations must be taken so that an accurate elemental time can be obtained.
• A start is then made on the drawing of the chart by setting out in bar form the activities of the leading operative or machine together with the time scale. The work cycles of other operatives or machines are then plotted in adjacent bars using the same timescale.
• The different sections within each bar should be colour coded, and the amount of effective work per cycle calculated as a percentage.
An example of a multiple activity chart is given in Figure 9.
Figure 9: Multiple activity chart for producing a letter, originated by a manager,
and typed by a secretary using a word processor
A multiple activity chart may be used to record activities in the following types of situation:
• one operative running one machine
• one operative running several machines
• several operatives running one machine
• several operatives running several machines
• a team of operatives
• a bank of machines.
It is essential that the multiple activity chart shows a representative section of the work being studied. The pace of the operation is controlled by the operative or machine whose job has the greatest work content.
Examination of the multiple activity chart will show the possibilities of elimination, change of sequence, combination and simplification which exist. For example, in the case of a man-machine relationship it may be possible to:
• install an additional machine
• introduce extra `inside cycle’ work to increase the operative utilisation percentage
• simplify loading and unloading procedures to minimise stopped time between operating cycles.
Go To Activity Eight
4.6 Step 3: Critical examination
3400: The systematic analysis of information about a problem, procedure or activity, by which it is subjected to exhaustive challenge with regard to need, simplification, combination, sequence and alternatives.
The purpose of critical examination is to determine the true reason underlying each event and to draw up systematically a list of all the possible improvements for later consideration and possible incorporation into a new and more effective method. This step is the crux of the basic procedure of method study and is dependent for its effectiveness on the accuracy and completeness of the recording of the present method.
Every aspect of the work being studied must be critically analysed in the light of the information recorded, much of it written on to critical examination sheets.
The whole examination procedure requires exhaustive collaboration with everyone who can offer useful information, and full use must be made of all sources of technical information. When examining the recorded facts of a process it is important that a systematic approach is followed from start to finish. The examination involves focusing on one step of the process at a time. The charting and subsequent analysis provide the work study officer with detailed facts about a process and the underlying reasons for each item on the chart. The work study officer is then in a position to review the process as a whole and again making full use of consultation, can seek the alternatives which will be the basis of any new methods.
Critical examination requires, above all, the correct attitude of mental self-discipline, in which the following guidelines should be followed:
• Facts must be examined as they are, not as they appear to be, should be, or are said to be.
• Preconceived ideas which often colour the interpretation of facts must be ruthlessly discarded.
• All aspects of the problem must be approached with a challenging and sceptical attitude. Every detail must be examined logically and no answer accepted until it has been proved correct.
• Hasty judgements must be avoided.
• Hunches should be committed to paper and then put away for consideration later in the study.
• New methods should not be considered until all the facts about the existing method have been exposed by systematic examination.
CLASSIFICATION OF OPERATIONS
Although transports and delays may, on the surface, appear to give the greatest scope for improvement, the best results are achieved by studying certain operations first.
Operations can be classified as:
• make ready operations: These are preparatory `operations’ concerned with the preparation of material, plant or equipment, which enable the actual work to be done.
• key operations: These represent the actual performance of work that adds value to the product and which normally result in a change in the properties or characteristics of the material.
• put away operations: These are concerned with the placing aside or clearing up after the `key’ operations.
The greatest room for improvement lies in eliminating the key operations for if this can be done, the `make ready’ and `put away’ operations associated with them will be eliminated, as well as corresponding delays and transports. Even if the key operations cannot be eliminated, questioning them first (where, when, how, etc.) offers the best chance of generating worthwhile alternatives since they constitute the framework around which the job as a whole is built up.
A thorough critical examination consists of three main stages:
• examination of the operation as a whole.
• detailed analysis of the key operations and/or inspections (known as the `key concept’)
• final analysis, where justified, of the `movements’, `delays’ and `storages’ arising from the second stage of the examination.
DETAILED CRITICAL ANALYSIS
This part of the procedure is the heart of method study and consists of a searching or detailed analysis of the key operations and inspections. Each of these key operations and inspections is treated separately for the purpose of critical analysis and is subjected to a systematic questioning procedure.
The examination is achieved by means of two sets of questions: the primary questions to establish the facts and the reasons underlying them, and the secondary questions to indicate the alternatives and consequently the possible improvements.
34006: The first stage in which the fundamental need for performing, each activity recorded, and its place, sequence, person and means are questioned and justification is sought for each reply.
The following are the primary questions under their respective headings:
Purpose: the questions What is achieved?, Is it necessary? and Why?, challenge the existence of the activity. If these questions show that an operation can be eliminated, it is not necessary to ask the remaining questions.
Place: the questions asked under this heading are: Where is it done? and Why then?
Person: the next questions refer to the person performing the activity. They are: Who does it? and Why that person?
Means: finally the means of carrying out the activity are challenged by asking How is it done? and Why that way?
The first question, What is achieved? is worth spending a lot of time on. We are critically examining an activity. The activity has an end-result ¬ the achievement. We are here questioning purpose, and purpose is a way of expressing theneed to achieve a particular result.
Critical examination is a logical way of generating new ideas. It will succeed only if the user has the courage and determination to follow up the implications of the answers to the questions asked.
34006: The second stage, in which the remaining essential activities are subjected to further questions to determine alternatives and to select those which are practicable and preferable
We are questioning the need for the (precisely-stated) results of an activity and asking: What else could be done or achieved?. Having completed the questioning of purpose, we can then proceed to consider place, sequence, person, etc. in the same way. For instance, Where is it done?, Why there? lead naturally to Where else could it be done?, similarly with When else?, Who else? and How else?
In all cases, the primary questions should be answered carefully and factually, in precise terms, covering all aspects. Alternatives can be easily generated by applying simple logic questions, for example, `not there’ implies somewhere else, hence, Where else might it take place? Similarly, `not then’, `not that person’, `not that way’ will be found to imply whole ranges of alternatives based on When else?, Who else? and How else? A guide sheet is often found to be helpful and is included as Resource 7.1.
As in all brainstorming approaches of this type, any alternatives generated should at first be listed uncritically. Only later should they be subjected to evaluation and tests for practicability and preferability. In the value analysis technique, a team approach at this stage is normal practice, and there is evidence that the same is desirable in method study at the critical examination stage. In the team approach, it is absolutely imperative to obey the rule `no criticism of ideas’ as they emerge, otherwise inspiration dries up.
Strictly speaking, when alternative possibilities have been generated for a particular activity (under What else could be done?, When else?, Where else? etc.) the critical examination is at an end and the evaluation or development stage starts. `Selection for development’ is sometimes included as part of critical examination, however. This is an assessment of the possibilities and is generally separated into short-term and long-term changes. The questions What should be done?, Where should it be done?, etc. are used to indicate this selection.
SUMMARY OF CRITICAL EXAMINATION
We can summarise the sequence of the examination to which each job and then each activity is subjected as follows:
Purpose What is achieved?
Is it necessary? Why?
What else could be done?
What should be done?
Place Where is it done?
Where else could it be done?
Where should it be done?
Sequence When is it done?
When else could it be done?
When should it be done?
Person Who does it?
Why that person?
Who else could do it?
Who should do it?
Means How is it done?
Why that way?
How else could it be done?
How should it be done?
Modern practice is to use a guide sheet as shown in Resource 7.2. A line is drawn across when each section is completed. An example of a partly completed guide sheet for a particular activity, in this case, packing goods into a carton, is shown in Resource 7.3
Go To Resource Item 7.1
Go To Resource Item 7.2
Go To Resource Item 7.3
Go To Activity Nine
Heuristic means discovery. It was originally used to study the methods and rules of discovery and invention. It follows a `trial and error’ approach.
The heuristic calculation of an answer to a problem follows this pattern:
• decide the solution required
• calculate a result from the known data
• is the result anything like the requirement?
• recalculate to bring the result nearer to requirement
• continue recalculating until the solution is reached.
Let’s look at a mathematical example:
square root of 24 is required
5 × 5 = 25
similar, but too high
try, 4.8. × 4.8 = 23.04
try, 4.92 × 4.92 = 24.10 etc., etc.
Heuristics can be used to handle ill-structured problems. We need to consider the present situation, and the kind of situation which we want to reach. We prepare a solution and compare it with the objective. Deficiencies are examined and another trial solution attempted. Heuristic reasoning is good in itself but if you are a thorough problem solver you may prefer the analytical approach when you can do this. An example of someone using a heuristic approach is the central heating installer. The task is to connect two pipes already installed with a further piece of pipe, which goes around an awkward bend. An analytical approach would demand a careful measurement of the situation, and then a drawing from which a suitable piece of pipe could be cut and bent in the workshop. Hopefully the piece of pipe would fit exactly. The heuristic approach would mean that the installer took a piece of pipe approximately of the right length and commenced to bend it to shape. By trial and error the right shape is reached and the pipe then cut to length and fitted it into the system. Here, the heuristic solution may achieve perfectly satisfactory results, in much less time.
Go To Activity Ten
4.7 Step 4: Developing the new method
Critical examination is closely linked with the development stage of the basic method study procedure. Amongst the points which will have been established are:
• Activities which are vital to the achievement of the objective.
• Sequences of vital activities which can be contemplated.
• Those activities which can be completely eliminated.
• Combinations of vital activities which are possible.
• Full range of alternatives with short- and long-term preferences.
The process of developing a new method consists of the formal evaluation of the possibilities available and the selection of the solution which best meets the objectives established at the beginning of the investigation. In development work it is essential to:
• work with facts, not opinions
• work on causes, not effects
• work with reasons, not excuses.
Possibly the best way to develop a new method is to select an ideal proposal to cover each essential activity, and then to obtain compatibility by minimal amounts of compromise on each proposal. The solution may, even then, be rejected in favour of something less attractive but cheaper and easier to implement.
The use of specially-designed development stage sheets (see Resource 7.4) is found helpful by many method study practitioners. A whole series of critical examination sheets are prepared prior to moving into the development stage. Remember that some degree of iteration may be necessary. You may need to go back to earlier stages before moving forward through the methodology again.
Go To Resource Item 7.4
PROCESS OF DEVELOPMENT
During the process of recording and examination the method study practitioner will have had a considerable amount of dealings with persons involved with various aspects of the task. At the development and evaluation stages, the process of consultation must continue until the practitioner is satisfied that the proposals are valid and realistic and can be put in a report for submission to line management. The groups of people likely to be involved in consultation over new method proposals would be:
• Line management, at the appropriate level for particular points.
• Technical specialists, who will give advice where design, quality or manufacturing changes are proposed.
• Works engineering personnel, where machine or layout modifications are desirable.
• Operatives and their representatives, particularly when trials and evaluations need to be performed.
Features of departmental layout will need consideration.
• Realistic proposals must be translated into a practical and detailed layout. The specific use of each square metre of floor space should be stated. The access to all work stations must be planned.
• Workplace storage areas need to be carefully designed.
• Consideration should be given to the nature of each process in the layout. If any have undesirable features which cannot be eliminated, effort should be made to minimise the effects of such features. For example, dust migration can be prevented by extraction or localised by plastic curtains. Sound can be baffled by carpeting offices.
• Ergonomic aspects must be built in.
• Gangways should be logically planned and provide access to and from all work areas. Selected width should relate to the nature and volume of traffic.
• Floor loading capacities should be borne in mind.
• The location of mains services (drains, steam, water, gas, electricity etc.) should be taken into account.
It is necessary to specify the type and quantities of work tables, trucks, racks, conveyors, containers, tools, jigs and fixtures, desks, computer terminals, lockers, filing cabinets etc. required in the new system. Trade literature will usually be consulted and the advice of outside suppliers, with quotations and delivery times, will normally be sought. Personnel matters
Personal matters will need consideration.
• Where working methods are changed, estimates of any effect in staffing levels must be made. Work measurement data will be particularly useful in this connection.
• Specific plans for dealing with labour which is superfluous to requirements must be drawn up in conjunction with the personnel function. The kind of options normally open are: transference within the firm or group; reduction by natural wastage; encouragement and help in finding alternative employment. In the case of redundancy, payments would obviously be a cost set against savings.
• Plans for training operatives in the new working methods must be prepared.
Fundamental changes will result in a need for revision of the system of recording and controlling output. Alterations to the paperwork and supervisory arrangements must be proposed in such circumstances. In order to be realistic, a proposal must satisfy the following:
• safety regulations. There must be no short cuts at the expense of operator safety, or infringement of factory or office legislation
• quality standards. Changes must not detract from quality standards laid down by specification
• stringent trials, tests and evaluations. These must satisfy all concerned of the validity of the proposals
• desired output levels. The original terms of reference must be kept in mind when assessing realistic output potential
• additional resource constraints. There must be the possibility of the required resources being made available.
4.8 Step 5: Installing the new method
By following the basic procedure of method study, the stage is eventually reached at which an improved method is ready to be discussed by all parties concerned. A formal report will have been prepared and circulated in advance of any arranged meeting. When a meeting is arranged, obviously any agreed negotiating procedures existing in the firm must be followed.
In situations where method changes are being proposed, various levels of management, operatives and their unions would normally be represented
Four separate phases in the installation stage can be discerned: selling the proposal, preparing for installation, commencing the new method and initial monitoring.
1. `SELLING’ THE PROPOSAL
The stage of convincing all parties concerned about the advantages of adopting the proposed method is often calledselling. Approval must be gained from the various people in the organisation affected by the proposal. The method study practitioner must convince management that he or she is competent and that real benefit will accrue from the proposal. He or she must convince the operatives and their trade union representatives that the work is factual and unbiased, and that the proposal will make easier and safer working procedures. Often, a method proposal is presented as part of a package, in which monetary matters are also raised for discussion.
Many questions will be raised during the discussions and the method study practitioner must be prepared to deal confidently and squarely with all matters. Lack of enthusiasm or a weak presentation will not commend the method proposal.
2. PREPARATION FOR INSTALLATION
A method proposal may require complete acceptance before any real preparation for installation can be undertaken. Machinery and plant may need to be purchased or structural alterations made. In such cases, once final decisions have been taken it may prove expensive to alter or cancel the plan at a later date.
The nature of some method proposals, however, permits a provisional acceptance on behalf of the parties concerned. There is often an undertaking that regular review meetings will take place in the weeks immediately following installation, and minor changes to the method made, as the need arises, with the consent of all parties.
The preparation stage can be viewed in three aspects: planning, arranging and rehearsing.
• One person only should be responsible for installation planning and all persons concerned should be aware of the identify of that person.
• Actual dates for each stage of installation should be fixed and published.
• All layouts must be checked in detail to ensure all the necessary plant, tools and equipment are available and services laid on.
• Old stocks of raw materials and bought-out parts must be progressively reduced, and the build-up of new supplies continued as the installation date draws near.
• New control systems must be set up.
• Arrangements must be made when a change of shift working is involved.
• Training in new methods must be provided, away from the working area if possible.
Rehearsals enable operatives to familiarise themselves with the new method, and various management specialists to check that their requirements are also likely to be met, for example quality controllers, who will want to be certain quality standards are going to be maintained, and plant engineers, who will want to ensure that no unsafe working practices are being introduced. Rehearsals or trial runs are often arranged outside normal working hours.
3. COMMENCEMENT OF THE NEW METHOD
• Physical changes of layout and stocks are best done just before the commencement of the method. Loss of output is minimised if comparatively simple changes are made over the weekend or more complex changes are made during the works’ shutdown period.
• Close supervision is essential during the first few days to ensure all persons concerned are co-operating and to give immediate decisions on snags which arise.
• Where any minor modifications have to be made in the early days with mutual agreement, they must be incorporated in the work specification
• Adequate stocks of materials and a free flow of containers, crates, trucks etc. must be maintained.
• There must be close liaison between the method study practitioner and relevant staff to ensure that installation strictly follows the prescribed plan.
• Devise and operate a performance monitoring system. Feed in data on a daily basis. This will be simpler if standard times and an incentive scheme are also being introduced with the method. Calculate daily performances on individual and group bases and feed back information to the department concerned.
• Determine the new levels of lost time, breakdowns, scrap and rectification and compare with the original system. Get such levels as low as possible.
• If an incentive scheme is being introduced, ensure any geared features operating during the lead-in period are applied, and reflected in wage payments.
• Collate and list all data obtained from the new system in readiness for discussion at the review meetings.
4. INITIAL MONITORING
• Devise and operate a performance monitoring system. Feed in data on a daily basis. This will be simpler if standard times and an incentive scheme are also being introduced with the method. Calculate daily performances on individual and group bases and feed back information to the department concerned.
• Determine the new levels of lost time, breakdowns, scrap and rectification and compare with the original system. Get such levels as low as possible.
• If an incentive scheme is being introduced, ensure any geared features operating during the lead-in period are applied, and reflected in wage payments.
• Collate and list all data obtained from the new system in readiness for discussion at the review meetings.
4.9 Step 6: Maintaining the new method
The installation stage ends with the new method operating smoothly at the expected output levels. The working practices at this stage should square up exactly with the details given in the work specification. (See example in Resource 7.5.)
An agreed working procedure can only be maintained by constant vigil on the part of the work study function. In almost any working environment, changes can occur within a comparatively short period, which will radically affect safety, quality and speed. The variations from standard practice which thereby arise, must be noted and evaluated.
Changes can occur in three main ways:
• deliberate alterations with good reason
• gradually and without intention
• deliberate but unauthorised changes by either operator or supervisor.
An efficient review policy will highlight such changes. The frequency of review will depend on the nature of the work.
Go To Resource Item 7.5
DELIBERATE ALTERATIONS WITH GOOD REASON
If changes of this nature are discovered by the review, when the working practices are compared with the work specification, the work study practitioner will:
• ascertain who authorised the change
• stress to that person the need for communication with the work study department on such matters, before any change is made
• investigate the effect of the change
• consult with all concerned on the findings and either revert, or amend both work specification and standard times.
The effect of the review will make management `method conscious’. The introduction of a formal system which indicates proposed or likely changes in advance to the operations management staff should be introduced. A suitable form to cover method changes can be designed and provided to appropriate staff and functional areas to record these method changes. An example is shown in Resource 7.6.
Go To Resource Item 7.6
CHANGES WHICH OCCUR GRADUALLY AND UNINTENTIONALLY
These kind of changes are often minute and almost imperceptible. For example, the oiling or servicing of a clamp makes operation easier. The repair of a bench results in new tool locations. These changes, when observed, must be evaluated and assessed. If beneficial, they must be formally incorporated into the work specification, and adjustment made to the standard times. If detrimental, there must be reversion back and an explanation given. If obvious `gaps’ have appeared in the system, which are undesirable, the practitioner must consider how they can be plugged.
DELIBERATE BUT UNAUTHORISED CHANGES
Deliberate but unauthorised changes may be carried out by:
• maintenance staff.
These changes, when observed, must be highlighted. The role of supervision must be stressed. The authority for change when a work studied specified job needs amendment is an agreement between the work study department, supervision and operator representatives that attention is required.
Go To Activity Eleven
4.10 Failure of projects
There are a number of reasons why some method study assignments do not lead to a successful application. It is fair to say, however, that if the detailed methodology is followed carefully through all stages there should be a high level of probability of a successful outcome. Where particular difficulties are identified during the assignment, they can either be addressed, or the assignment suspended or aborted. Here are some of the reasons why a completed assignment is never actually installed:
• circumstances have changed since the study began
• management dislikes certain features in the proposal
• opposition from the staff who are involved
• unwillingness of management to provide resourcing.
Go To Activity Twelve
In this section we examined in detail the contribution of work study to job design, problem solving, and to setting standards and motivating staff. We considered each of the six steps (SREDIM) in the method study approach and related considerations and techniques.
SECTION 5: Work Measurement
Having established the need for sound, safe and productive work methods, we now consider the time content of jobs. This factor needs careful determination because it can be applied to many issues. Its importance was realised centuries ago, and recorded details of time studies undertaken by Leonardo da Vinci (Italy) and Jean Perronet (France) exist. We will look at the basic procedure of work measurement and then at the techniques of time study, activity sampling, predetermined time motion standards and analytical and comparative estimating. We discuss briefly financial incentive schemes.
Clandestine time studies were being undertaken in the UK in the 1790s in the pottery industry for production planning, and Charles Babbage, the Cambridge University mathematician, was an industrial adviser on time study and cost accounting in the 1830s. The whole concept of precise and detailed time study was brought into focus through the work of F W Taylor (USA) in the late 1800s. The philosophy which underpinned Taylor’s work can be summarised:
• developing a science for each element of a person’s work to replace guesswork
• selecting best worker for each particular job
• training, teaching and developing each worker in the job
• improving management/staff co-operation q apportioning of work to allocate equal shares of responsibility to both management and staff.
Although many of Taylor’s objectives were not fully achieved in his lifetime, and there have been many critics of his approach, it is interesting to relate them to the business situation today. The last two in the list given, for example, sit very comfortably in a total quality framework.
The article `Roots’, Resource Item 1.1, gives further information about the work of some of the pioneers in this field.
Go To Resource Item 1.1 5.1 Methodology
10004: Work measurement is the application of techniques designed to establish the time for a qualified worker to carry out a task at a defined rate of working.
Work measurement provides management with a means of measuring the time taken to perform of an operation so that ineffective time can be highlighted. It is used for:
• comparing the effectiveness of different methods
• balancing the work of team members
• determining operator machine loadings
• providing planning and scheduling data
• providing cost estimates, delivery dates, selling prices
• setting standards of machine utilisation
• designing incentive schemes to stimulate labour performance
• providing data for a labour cost control system.
Work measurement provides the basic information necessary for all the activities of organising and controlling the work of an enterprise in which the time element plays a part. Work measurement techniques in use are:
• time study
• activity sampling and rated activity sampling
• predetermined motion time standards
• analytical and comparative estimating.
THE BASIC PROCEDURE
As for method study, a systematic six-step approach is used:
1. Select the work to be studied.
2. Record all the relevant data relating to the circumstances in which the work is being done, the methods and the elements of activity in them.
3. Measure each element in terms of time over a sufficient number of cycles of activity to ensure that a representative picture has been obtained.
4. Examine the recorded data and element times critically to ensure that unproductive or random elements are separated from productive elements. Examine the recorded times of each element and determine a representative time for each.
5. Compile a time for the operation which will provide a realistic standard of performance and will include time allowances to cover suitable rest, personal needs, contingencies etc.
6. Define precisely the series of activities and method of operation for which the time has been allowed and issue the time as standard for the activities and methods specified.
We use a methodology like the six-step approach in applying work measurement so that we will work efficiently. It is easy for many important details to be missed which will invalidate the actual standard minute value. For example, we may include elements which really need to be excluded, or undertake work which is already on file, having been done before.
5.2 Time study
Once the work has been selected for study, the time study practitioner has to decide which technique is appropriate. If the approach selected involves time study, the following steps must be undertaken:
• Obtain all relevant details about the job, the operator, the machine and its environment, together with a complete description of the method.
• Attend to the normal industrial relations courtesies which should precede all study work.
• Make a number of fairly broad-detail time study observations of the main parts of the job.
• Decide on an appropriate elemental breakdown and define breakpoints.
• Select appropriate study periods.
• Undertake a series of time studies, and measure the time taken by the operator to perform each element. Assess working performance levels for each completed element of work.
• Ensure work study covers all aspects of the job.
The practitioner then analyses this work measurement data to produce information in the form in which it is required, for example as a basis for an incentive scheme. A special kind of stop watch is normally used for time study, although many practitioners are now being trained in the use of computerised time study boards. The advantage of these systems is the greatly reduced analysis time following study work. Times are normally recorded in 1/100ths of a minute (deciminutes or centiminutes). Care should be taken in describing time values in terms of the unit used, for example 0.60 centiminutes is equal to 36 seconds.
• Flyback analogue-type watch: The hands return to zero every time the central plunger is depressed. The slide on the side of the watch is used to start and stop it.
• Flyback digital-type watch: Often this watch has a built-in memory function and will show cumulative times.
• Computerised study board systems.
TIME STUDY PROCEDURE
Before undertaking a time study, various courtesies need to be attended to. These involve discussions with personnel concerned and their supervisors. Time study must not be undertaken secretly. All data should be available for inspection and verification.
Prior to time study, the operation must be broken down into elements.
42003: an element is a distinct part of an operation selected for convenience of observation, measurement and analysis.
42002: a breakpoint is the instant at which one element in a work cycle ends and another begins.
Jobs are broken down into elements for a variety of reasons:
• Variations in operator speed and effectiveness can be more accurately assessed over short periods.
• Relaxation allowances can be more accurately determined.
• Productive and unproductive work can be separated.
• To enable appropriate frequency factors to be applied to repetitive elements in the compilation of a standard time value.
• Elemental times can be used in the compilation of synthetic standard times, and in analytical estimations.
Different types of element are recognised:
42007: repetitive elements occur in every work cycle of an operation.
42006: occasional elements do not occur in every work cycle of an operation but may occur at regular or irregular intervals.
42004: constant elements are elements for which the basic time remains constant whenever it is performed.
42005: variable elements in which the basic time varies in relation to some characteristics of the product, equipment or process, for example, dimensions, weight, quality etc.
42010: manual elements which are performed by the operator.
42011: machine elements which are automatically performed by a power-driven machine (or process).
42008: governing elements which occupy a longer time than that of any other element which is being performed concurrently.
42009: foreign elements are elements observed during a study which, after analysis, are found to be an unnecessary part of an operation.
Go To Activity 13
Whilst timing a job, the work measurement practitioner also `rates’ the performance of the operator. Accuracy in rating comes from specialised training using films of typical work sequences and wide practical experience. Many organisations keep their practitioners in line with the use of `rating clinics’ at regular intervals. These are often set up and administered by the local college or university. It is also common for trade union representatives to be included in these clinics so that meaningful discussions about working performance can be held.
Normally a rating factor is written alongside each element of effective time recorded on the study sheet.
41018: rating is the numerical value given to a rate of working.
The practitioner may take into account, separately or in combination, one or more factors necessary to carry out the job such as: speed of movement, effort, dexterity, consistency.
41025: standard rating is the rating corresponding to the average rate at which qualified workers will naturally work, provided they adhere to the specified method and provided they are motivated to apply themselves to their work.
If the standard rating is consistently maintained and the appropriate relaxation is taken, a worker will achieve standard performance over the working day or shift.
The practitioner must bear in mind the following issues whilst rating:
• a representative motion pattern for performing the elements of work
• the speed of movement which would be present if the operative were suitably motivated
• effort must be considered from a range of speeds which could be expected under varied conditions, for example, walking on the flat, walking unladen uphill, walking with load uphill, etc.
It is important in rating that only the effective speed at which the operation is performed is judged. Trained operatives should not vary in effectiveness. It is obviously possible to work very fast yet include in the motion pattern many undesirable and over elaborate movements which thereby reduce effectiveness. Highly skilled operatives may appear to be working slowly yet, because every movement is effective they will complete the task in a relatively short time. Consequently, the skills and method of a job should be properly understood by the observers so that accurate assessments of effective speed can be made.
As with all scales of measurement certain fixed points must be established. Two points are quoted in connection with the rating scale. The lower fixed point is the expected speed and effectiveness over a time period from a worker, skilled and accustomed to his task, who is not working under any particular incentive, monetary or otherwise. This is commonly likened to a 3 mph walking pace and known as normal performance.
The upper fixed point, called standard performance, has already been defined. It is the speed and effectiveness expected from a skilled and experienced operator working in good conditions and suitably motivated. The performance level attained is likened to 4 mph walking pace.
Figure 11 shows the BSI rating scale.
Figure 11: BSI rating scale
With practice a high degree of accuracy can be obtained and ratings are normally taken throughout a range of studies so that minor errors will tend to be cancelled out.
Go To Activity 14BASIC TIMES
On completion of a time study, the times recorded for each element are adjusted by means of the rating to give thebasic time for each element. We can extend this to basic minutes (BMs).
43023: the time for carrying out an element of work at standard rating.
It is calculated in the following way:
For example, OT = 0.30, R = 90
Basic time = 0.27 BMs.
Go To Activity 15DETERMINING A REPRESENTATIVE ELEMENTAL BASIC TIME
Normally, a number of readings will be taken of each element occurring in the work sequence. Sometimes there may be hundreds of readings on certain repetitive elements. Each observed elemental time is extended by its rating to give the basic time. A time study analysis sheet can be used to group all the basic times for the same elements.
A decision is then taken as to how a representative elemental time can be established. In many cases, a straight average can be taken. It is advisable, however, to scrutinise the list of basic times carefully to eliminate any which are grossly out of line because of abnormal circumstances, before taking the average.
Some practitioners plot the basic times in the form of a histogram and produce a distribution curve. The median is calculated and used as the elemental basic time.
Where an element is variable with respect to a particular feature, for example, weight or size of product, graphical analysis is necessary to produce a range of basic times relative to that variable feature.
For example, consider a simple two element job.
Time study sheet extract is shown in Table 1.
Element Rating Observed time Basic time
1 90 .30 .27
2 100 .40 .40
1 100 .27 .27
2 110 .38 .42
1 100 .28 .28
2 70 .56 .39
1 120 .23 .28
2 100 .41 .40
1 70 .40 .28
2 100 .40 .40
Table 1: Time study sheet extract Time study analysis sheet extract is shown in Table 2.
Element 1 Element 2
Total 1.38 2.02
Occurances 5 5
Average BMs 0.28 .40
Table 2: Time study analysis sheet extract
43025: Relaxation allowance (RA) is an addition to the basic time to provide a qualified worker with a general opportunity to:
• recover from the effort of carrying out specified work under specified conditions (fatigue allowance)
• allow attention to personal needs
• recover from adverse environmental conditions
The amount of the allowance will depend on the nature of the job.
The levels of allowance given in Table 3 are intended to enable an average and suitable worker to maintain a 100 performance over the whole of the working day, without becoming more than ordinarily tired. The assessment of relaxation allowance must never be included in the rating assessment. The allowances are awarded under six categories to each element on the relaxation allowance sheet.
The total RA for an element is added as follows:
• personal needs (A)
• effort (B)
• posture (C)
• eye and mental attention (D)
• abnormal conditions (E)
• monotony (F).
If the total RA% for a job as a whole adds up to, say, 20% of the total basic time for the job, it is a strong indication that the method should be carefully reconsidered.
We do not claim that the relaxation allowances in Table 3 are absolutely correct, but by using the table and awarding the allowances elementally, we can be sure of two things:
• the relaxation allowance is reasonably adequate
• the allowances given for comparable jobs are identical.
A constant allowance is given to cover purely personal needs and tea breaks.
This allowance is given to compensate for cumulative muscular fatigue resulting from the use of the muscles in lifting, pushing or pulling loads. We choose the allowance after taking into account:
• the intermittence or continuity of handling
• the ease or difficulty of handling ¬ compactness, bulkiness, rigidity or floppiness of the load
• the proportion of the element during which the worker is under load.
This allowance is given when the work is done other than in the normal sitting position. But remember that a seated worker may have to reach with body assistance. This would be classified as other than `normally seated’. The proportion of the element time spent standing, crouching, bending or reaching will influence the award.
Eye and mental attention
Some jobs, even under conditions of good lighting, will cause eye strain and in a few jobs there is some mental strain involved. In deciding upon the size of this allowance it is useful to slot the element in question into a scale running from zero for work similar to tossing a small object into a packing case, to 10% for, say, fitting a hairspring in a wrist watch. The element being considered may fall perhaps nearer to the zero end of the scale than to the half-way mark.
The important thing to remember is that if there is an award under this category, its purpose is to enable the worker to leave the job for a time and still produce a 100 performance at the end of the day.
Awards may be given to compensate for the hindrance caused by having to wear special clothing, excessive heat or cold, excessive humidity or fumes, and a poor environment. Up to 20% may be awarded under this one category in a very exceptional case. It is worth calculating which is the cheaper alternative; to allow the abnormal conditions to continue and to pay for them as non-productive time in the form of an allowance, or to pay to have the conditions improved and not give an allowance.
Awards under this category can be made for highly repetitive work, for example in light assembly work.
Guide to relaxation allowances
Table 3 is an example of a widely used guide, which can be used for either male or female operatives.
Category Heading Description % Allowance range
A Personal needs 6
B Effort 0-2.2kg (Seated light assembly work) 5
2.21-4.5kg (Walking unloaded) 6
4.5-6.7kg (Light manual work) 8
6.71-9.0kg (Sawing plank of wood) 11
9.1-11.3kg (Climbing upstairs unloaded) 14
11.4-13.5kg (Shovelling coal) 18
13.6kg (Digging heavy soil) 22
C Posture Sitting work 0
Standing work 2
Crouching / kneeling work 5
D Eye and mental attention Toss small object into large crate 0
Inspect finished garment 5
Fit hairspring to watch 10
E Conditions Special clothing e.g. light overalls 0
(0-5) Diving suit 5
Thermal conditions e.g. normal heat or cold 0
Outdoor work 3
Furnace or cold store work 5
Atmospheric conditions humidity, fumes etc 0-5
Environmental noise, dirt, poor light etc 0-5
F Monotony Little 0
High (repetitive short cycle work) 5
Table 3: Relaxation allowances
Go To Activity 16OTHER ALLOWANCES
In some work situations additional allowances will be added to the basic time. Detailed explanation of such allowances is beyond our scope here.
For definitions of these allowances consult the British Standards document BS 3138, Glossary of terms used in work study and organisation and methods. All definitions quoted come from this publication.
SUMMARY OF TIME STUDY PROCEDURE
• Convert the `observed’ times for each element into `basic’ times.
• Compile study basic times on an analysis sheet.
• Select appropriate elemental times using averaging, graphical or other statistical approaches.
• Determine the amount of relaxation and other allowances required for each element.
• Establish the frequency with which each element occurs in the work cycle.
• Compile a `standard time value’ for the job.
Figure 12 may help to clarify the way in which the different allowances are applied.
5.3 Activity sampling
This technique, which was devised by Tippett in 1934, consists of taking a series of instantaneous observations at random times to gather data about the activity levels in a situation. Certain statistical concepts underpin the technique. These are primarily associated with the laws of probability and the properties of the normal distribution curve.
To undertake an activity sampling survey, we follow these steps:
• Select the subject area and identify the features to be observed.
• Design a suitable recording form.
• Determine the number of observations which will be required for a pilot study using the formula:
P = estimated % occurrence of a main activity (or non-activity)
L = accuracy required (known as the confidence limits).
• Obtain and group enough random times to cover the work periods to be studied over a representative phase of the work process. Insert these random times on the recording form and arrange the studies.
• When studying, it is necessary to observe the subject(s) at the random time, and to record what is happening at that particular moment.
• When the study is complete, all recordings are totalled up for each category and the accuracy determined using:
P = actual % occurrence of the category
N = total observations made on the whole study.
If the accuracy achieved is outside of the required range, then recalculate N using the revised % for P. Undertake any additional study work, add on, recalculate etc.
Date: 4 January Section Department
Random Time Administration Category Computer
A B C D E F G
Let’s consider an example that concerns the utilisation of the forklift truck in the Parts and Raw Material Warehouse of Sunrise Engineering Co. Ltd.
Estimate of utilisation (given by manager) 35%, that is 65% idle.
Accuracy required: ± 5%.
A pilot study of 375 readings was decided on, spread over three weeks, 125 readings per week were taken.
This is within the accuracy range required so the 37% utilisation can be accepted. Utilisation range = (37% ¬ 5%) to (37% + 5%), that is, 32 to 42%. If you are statistically inclined, we can say that there are 95 chances in 100 that the true working % lies between 32% and 42%. This is based upon the formulas derived from the normal distribution curve and relates to the area enveloped by two standard deviations.
There are many tables of random numbers available. They have usually been produced by a computer. Random numbers are essential for an activity sampling exercise, but they must first be converted into clock times. This can be done by using the random numbers shown below:
Random hours covering 07.00 to 18.00 (7.00 am – 600 pm)
07 17 09 14 16 11 15 12 11 13 17 07
17 08 17 13 07 08 13 09 07 11 09 08
07 17 13 10 08 07 14 14 13 08 10 13
10 09 08 08 11 16 08 17 17 14 15 15
09 11 15 11 09 08 16 08 08 16 15 12
11 09 09 10 11 07 07 15 08 10 10 09
08 13 12 17 11 11 16 09 16 13 15 11
13 09 15 09 17 10 15 16 15 13 12 10
09 11 13 11 09 15 16 12 11 10 08 16
Random minutes (00 – 59)
02 49 59 26 39 45 12 32 18 56 10 03
22 02 43 19 23 55 39 05 09 17 44 52
00 01 03 34 38 27 29 26 24 44 15 54
31 26 10 06 11 05 47 41 01 23 53 42
26 13 16 01 51 43 07 42 21 05 24 57
34 56 36 31 41 17 44 50 25 52 02 03
45 07 16 18 42 51 33 55 43 20 46 54
23 09 21 01 04 23 08 04 23 52 38 01
17 43 07 38 19 54 40 40 36 54 07 58
14 04 50 10 11 25 36 00 39 37 59 59
34 16 05 29 25 28 30 32 35 58 02 51
35 08 52 47 52 10 05 36 02 48 17 31
• Decide the number of readings required per working period, for example, between 08.00 ¬ 12.00 and 13.00 ¬ 17.00.
• Select the number of readings required from the random hours table, for example, 20 readings 09, 13, 08, 11,…
• Select the number of readings required from the random minutes table, for example, 20 readings 02, 22, 00, 31,…
• Compile a list of times, for example, 09.02, 13.22, 08.00, 11.31…
• Put the times into logical order and add to the study sheets.
RATED ACTIVITY SAMPLING
This technique includes a rating assessment with the instantaneous samples taken, and is often used to determine elemental times within a job.
5.4 Predetermined Motion Time Standards (PMTS)
This method of determining standard time values is widely used in administration, manufacturing and maintenance situations. Time values for human movements at standard performance level (100) have been built up from the analysis of hundreds of film and video studies of work routines. From these studies, times have been categorised and published in tabular format. The practitioner needs to be able to analyse the method of the job in a certain way and then use the data provided.
One popular PMTS approach is known as MTM (Methods-Time-Measurement). In fact there are a series of MTM systems which vary in complexity:
MTM 1 which is extremely detailed
MTM 2 which is a useful compromise
MTM 3 which uses rather broader definition.
Many proprietary types of pre-determined time standards are available. These have been developed by research establishments and consultants for particular applications, for example, office work, engineering craft work etc.
To become a competent practitioner in pre-determined motion time standards, you would need to obtain qualifications through a specialised course.
Some organisations use PMTS as the vehicle for producing all time standards as there is a problem associated with taking of time studies. Other businesses use both PMTS and conventional time studies.
5.5 Estimating systems
We give the definitions of the two main techniques, but fuller explanation is beyond the scope of this unit.
41005: Analytical Estimating ¬ this is a development of estimating in which the time required to carry out elements at a defined rate of working is estimated partially from knowledge and practical experience of the work concerned and partially from synthetic data.
41006: Comparative Estimating ¬ this a technique in which the time for a task is evaluated by comparing the work in it with the work in a series of similar tasks (benchmarks), the work contents of which have been measured. The arranging of tasks into broad bands of time is referred to as slotting.
5.6 Financial incentive schemes
We can use standard minute values to determine output potential. Let’s look at an example. A word processing operator working in a mail order business deals with outgoing customers’ orders and after time study, a value of 8.42 SMs per order has been calculated.
As the operator works an 8 hour day (480 minutes) his or her supervisor knows that he or she should be able to deal with:
This is provided he or she works at standard performance (100 rating level) and only takes the allocated amount of allowance time.
We can calculate the number of operations required at different times of the year as seasonal demands vary. For example, in the spring build-up of summer business, 600 orders per day are being handled.
We can also calculate a performance level if a financial incentive scheme is applied.
For example, an operator produces 51 orders/day.
This can be equated in financial terms to a level of bonus earnings. Specific financial scheme design is beyond our scope in this unit. However, you should carefully consider the following general comments on incentives.
BASIC PRINCIPLES FOR A SUCCESSFUL FINANCIAL INCENTIVE SCHEME
If a financial incentive scheme is to operate successfully, the following conditions should be realised:
• There should be complete frankness and honesty on the part of management.
• The scheme should be equitable between employer and employee, and should ultimately contribute to the benefit of both.
• The scheme should be acceptable to the employees and so operated that they will have confidence in it.
• The scheme should be simple to understand and operate, and an adequate write-up should be provided for the operation.
• The incentive should be substantial (a weak incentive is useless).
• A person’s reward should be related to factors (quantity, quality, etc.) which they control.
• Notification of bonus earnings should be prompt, daily or weekly for preference.
• There should, in general, be no arbitrary limits to the amount of bonus that may be earned.
• The scheme must provide just penalties for substandard or spoiled work.
• Operators should not suffer any loss of earned bonus due to causes beyond their control, for example, waiting for materials.
• In no circumstances may a rate or time be altered once it has been set, unless there has been a clerical error, a change in the method of doing the job, or full agreement with the people involved
• The scheme should be applied individually wherever possible: if it must be applied to a `group’, the `group’ should be as small as possible.
• All standard times should be accurately determined.
• The scheme should be designed to assist supervision in their day-to-day management.
• Complaints and queries should receive prompt attention.
In this section we considered the time content of jobs. We looked at the basic six step procedure of work measurement and then at the techniques of time study, activity sampling, pre-determined motion time standards and analytical and comparative estimating systems. We ended with a brief look at financial incentive schemes.
In this unit we looked at issues which impinge upon effective management from an operations management perspective. We began by examining features of Japanese and Western organisations to highlight factors which lead to employee motivation and commercial success. We identified the inputs of resources which are utilised in manufacturing, administrative and service systems and considered the concept of productivity measurement and improvement. Finally we introduced and discussed important productivity-raising techniques used by many operations managers: method study and work measurement.
You can probably see now why there is a close relationship between the methods employed to achieve an objective and the time value allocated to the task. Ideally standard time values should be allocated to the task. These time values should be related to sound and efficient work methods which have been carefully designed and clearly specified to maximise job satisfaction and output quality. In such circumstances, with the appropriate managerial skills and resourcing, an organisation can expect to be able to operate at high productivity levels.
Alderfer, CP (1972) Existence, Relatedness and Growth: Human Needs in Organizational Settings, Free Press, NewYork
Hellriegel, D, Slocum J W and Woodman, R W (1989) Organizational Behaviour, West Publishing, New York
Lessem, R and Neubauer, F (1994) European Management Systems, McGrawHill, New York
Alkhafaji, A F (1995) Competitive Global Management, St Lucie Press, Florida
Currie, R M (1977) Work Study, Pitman, London
International Labour Office (1980) Introduction to Work Study, Geneva
Lorriman, J and Kenjo, T (1994) Japan’s Winning Margins, Oxford University Press, Oxford