Work Measurement and Job Design PDF

**7.1 INTRODUCTION** The importance of work design is underscored by an organization's dependence on human efforts (i.e., work) to accomplish its goals. Furthermore, many of the topics in this chapter are especially relevant for productivity improvement and continuous improvement. **7.2 JOB DESI...

**7.1 INTRODUCTION** The importance of work design is underscored by an organization's dependence on human efforts (i.e., work) to accomplish its goals. Furthermore, many of the topics in this chapter are especially relevant for productivity improvement and continuous improvement. **7.2 JOB DESIGN** Job design involves specifying the content and methods of jobs. Job designers focus on what will be done in a job, who will do the job, how the job will be done, and where the job will be done. The objectives of job design include productivity, safety, and quality of work life. Current practice in job design contains elements of two basic schools of thought. One might be called the efficiency school because it emphasizes a systematic, logical approach to job design; the other is called the behavioral school because it emphasizes satisfaction of wants and needs. The efficiency approach, a refinement of Frederick Winslow Taylor's scientific management concepts, received considerable emphasis in the past. The behavioral approach followed and has continued to make inroads into many aspects of job design. It is noteworthy that specialization is a primary issue of disagreement between the efficiency and behavioral approaches. **Specialization** The term specialization describes jobs that have a very narrow scope. Examples range from assembly lines to medical specialties. College professors often specialize in teaching certain courses, some auto mechanics specialize in transmission repair, and some bakers specialize in wedding cakes. The main rationale for specialization is the ability to concentrate one's efforts and thereby become proficient at that type of work. Sometimes the amount of knowledge or training required of a specialist and the complexity of the work suggest that individuals who choose such work are very happy with their jobs. This seems to be especially true in the "professions" (e.g., doctors, lawyers, professors). At the other end of the scale are assembly-line workers, who are also specialists, although much less glamorous. The advantage of these highly specialized jobs is that they yield high productivity and relatively low unit costs, and they are largely responsible for the high standard of living that exists today in industrialized nations. Unfortunately, many of the lower-level jobs can be described as monotonous or downright boring, and are the source of much of the dissatisfaction among many industrial workers. While some workers undoubtedly prefer a job with limited requirements and responsibility for making decisions, others are not capable of handling jobs with greater scopes. Nonetheless, many workers are frustrated, and this manifests itself in turnover and absenteeism. In the automotive industry, for example, absenteeism runs as high as 20 percent. Workers may also take out their frustrations through disruptive tactics such as deliberate slowdowns. The seriousness of these problems caused job designers and others to seek ways of alleviating them. [Advantages] For management: Simplifies training High productivity Low wage costs For employees: Low education and skill requirements Minimum responsibilities Little mental effort needed Behavioral Approaches to Job Design In an effort to make jobs more interesting and meaningful, job designers frequently consider job enlargement, job rotation, job enrichment, and increased use of mechanization. **Job enlargement** means giving a worker a larger portion of the total task. This constitutes horizontal loading---the additional work is on the same level of skill and responsibility as the original job. The goal is to make the job more interesting by increasing the variety of skills required and by providing the worker with a more recognizable contribution to the overall output. For example, a production worker's job might be expanded so that he or she is responsible for a sequence of activities instead of only one activity. **Job rotation** means having workers periodically exchange jobs. This allows workers to broaden their learning experience and enables them to fill in for others in the event of sickness or absenteeism. Job enrichment involves an increase in the level of responsibility for planning and coordination tasks. It is sometimes referred to as vertical loading. An example of this is to have stock clerks in supermarkets handle the reordering of goods, thus increasing their responsibilities. The job enrichment approach focuses on the motivating potential of worker satisfaction. Job enlargement and job enrichment are also used in lean where workers are cross-trained to be able to perform a wider variety of tasks and given more authority to manage their jobs. The importance of these approaches to job design is that they have the potential to increase the motivational power of jobs by increasing worker satisfaction through improvement in the quality of work life. Motivation Motivation is a key factor in many aspects of work life. Not only can it influence quality and productivity, it also contributes to the work environment. People work for a variety of reasons in addition to compensation. Other reasons include socialization, self-actualization, status, the physiological aspects of work, and a sense of purpose and accomplishment. Awareness of these factors can help management to develop a motivational framework that encourages workers to respond in a positive manner to the goals of the organization. A detailed discussion of motivation is beyond the scope of this book, but its importance to work design should be obvious. Another factor that influences motivation, productivity, and employee--management relations is trust. In an ideal work environment, there is a high level of trust between workers and managers. When managers trust employees, there is a greater tendency to give employees added responsibilities. When employees trust management, they are more likely to respond positively. Conversely, when they do not trust management, they are more likely to respond in less desirable ways. **Teams** The efforts of business organizations to become more productive, competitive, and customeroriented have caused them to rethink how work is accomplished. Significant changes in the structure of some work environments have been the increasing use of teams and the way workers are paid, particularly in lean production systems. In the past, nonroutine job assignments, such as dealing with customer complaints or improving a process, were typically given to one individual or to several individuals who reported to the same manager. More recently, nonroutine assignments are being given to teams who develop and implement solutions to problems. There are a number of different forms of teams. One is a short-term team formed to collaborate on a topic such as quality improvement, product or service design, or solving a problem. Team members may be drawn from the same functional area or from several functional areas, depending on the scope of the problem. Other teams are more long term. One form of long-term team that is increasingly being used, especially in lean production settings, is the self-directed team. Self-directed teams, sometimes referred to as self-managed teams, are designed to achieve a higher level of teamwork and employee involvement. Although such teams are not given absolute authority to make all decisions, they are typically empowered to make changes in the work processes under their control. The underlying concept is that the workers, who are close to the process and have the best knowledge of it, are better suited than management to make the most effective changes to improve the process. Moreover, because they have a vested interest and personal involvement in the changes, they tend to work harder to ensure that the desired results are achieved than they would if management had implemented the changes. For these teams to function properly, team members must be trained in quality, process improvement, and teamwork. Self-directed teams have a number of benefits. One is that fewer managers are necessary; very often one manager can handle several teams. Also, self-directed teams can provide improved responsiveness to problems, they have a personal stake in making the process work, and they require less time to implement improvements. Generally, the benefits of teams include higher quality, higher productivity, and greater worker satisfaction. Moreover, higher levels of employee satisfaction can lead to less turnover and absenteeism, resulting in lower costs to train new workers and less need to fill in for absent employees. This does not mean that organizations will have no difficulties in applying the team concept. Managers, particularly middle managers, often feel threatened as teams assume more of the traditional functions of managers. Moreover, among the leading problems of teams are conflicts between team members, which can have a detrimental impact on the effectiveness of a team. Expert **[Robert Bacal]** has a list of requirements for successful team building:1 1\. Clearly stated and commonly held vision and goals. 2\. Talent and skills required to meet goals. 3\. Clear understanding of team members' roles and functions. 4\. Efficient and shared understanding of procedures and norms. 5\. Effective and skilled interpersonal relations. 6\. A system of reinforcement and celebration. 7\. Clear understanding of the team's relationship to the greater organization. **Ergonomics** Ergonomics (or human factors) is the scientific discipline concerned with the understanding of interactions among humans and other elements of a system, and the profession that applies theory, principles, data, and methods to design in order to optimize human well-being and overall system performance. "Ergonomists contribute to the design and evaluation of tasks, jobs, products, environments and systems in order to make them compatible with the needs, abilities and limitations of people."2 In the work environment, ergonomics also helps to increase productivity by reducing worker discomfort and fatigue. The International Ergonomics Association organizes ergonomics into three domains: physical (e.g., repetitive movements, layout, health, and safety); cognitive (mental workload, decision making, human--computer interaction, and work stress); and organizational (e.g., communication, teamwork, work design, and telework).3 Many examples of ergonomics applications can be found in operations management. In the early 1900s, Frederick Winslow Taylor, known as the father of scientific management, found that the amount of coal that workers could shovel could be increased substantially by reducing the size and weight of the shovels. Frank and Lillian Gilbreth expanded Taylor's work, developing a set of motion study principles intended to improve worker efficiency and reduce injury and fatigue. In the years since then, technological changes have broadened the scope of ergonomics, as hand--eye coordination and decision making became more important in the workplace. More recently, the increasing level of human--computer interfacing has again broadened the scope of the field of ergonomics, not only in job design, but also in electronics product design. Poor posture can lead to fatigue, low productivity, and injuries to the back, neck, and arm. Good posture can help avoid or minimize these problems. Figure 7.1 illustrates good posture when using a computer. **7.3 QUALITY OF WORK LIFE** People work for a variety of reasons. Generally, people work to earn a living. Also, they may be seeking self-realization, status, physical and mental stimulation, and socialization. Quality of work life affects not only workers' overall sense of well-being and contentment, but also worker productivity. Quality of work life has several key aspects. Getting along well with coworkers and having good managers can contribute greatly to the quality of work life. Leadership style is particularly important. Also important are working conditions and compensation, which are addressed here. **Working Conditions** Working conditions are an important aspect of job design. Physical factors such as temperature, humidity, ventilation, illumination, and noise can have a significant impact on worker performance in terms of productivity, quality of output, and accidents. In many instances, government regulations apply. **Temperature and Humidity. Although human beings can function under a fairly wide** **range of temperatures and humidity, work performance tends to be adversely affected if temperatures** **or humidities are outside a very narrow comfort band. That comfort band depends** **on how strenuous the work is; the more strenuous the work, the lower the comfort range.** **Ventilation. Unpleasant and noxious odors can be distracting and dangerous to workers.** **Moreover, unless smoke and dust are periodically removed, the air can quickly become stale** **and annoying.** **Illumination. The amount of illumination required depends largely on the type of work** **being performed; the more detailed the work, the higher the level of illumination needed for** **adequate performance. Other important considerations are the amount of glare and contrast.** **From a safety standpoint, good lighting in halls, stairways, and other dangerous points is** **important** **Noise and Vibrations. Noise is unwanted sound. It is caused by both equipment and** **humans. Noise can be annoying or distracting, leading to errors and accidents. It also can** **damage or impair hearing if it is loud enough. Figure 7.2 illustrates loudness levels of some** **typical sounds.** **Vibrations can be a factor in job design even without a noise component, so merely eliminating** **sound may not be sufficient in every case. Vibrations can come from tools, machines,** **vehicles, human activity, air-conditioning systems, pumps, and other sources. Corrective** **measures include padding, stabilizers, shock absorbers, cushioning, and rubber mountings.** Work Time and Work Breaks. Reasonable (and sometimes flexible) work hours can provide a sense of freedom and control over one's work. This is useful in situations where the emphasis is on completing work on a timely basis and meeting performance objectives rather than being "on duty" for a given time interval, as is the case for most retail and manufacturing operations. Work breaks are also important. Long work intervals tend to generate boredom and fatigue. Productivity and quality can both deteriorate. Similarly, periodic vacation breaks can give workers something to look forward to, a change of pace, and a chance to recharge themselves. Occupational Health Care. Good worker health contributes to productivity, minimizes health care costs, and enhances workers' sense of well-being. Many organizations have exercise and healthy-eating programs designed to improve or maintain employees' fitness and general health. Safety. Worker safety is one of the most basic issues in job design. This area needs constant attention from management, employees, and designers. Workers cannot be effectively motivated if they feel they are in physical danger. From an employer standpoint, accidents are undesirable because workers can be injured, they are expensive (insurance and compensation); they usually involve damage to equipment and/or products; they require hiring, training, and makeup work; and they generally interrupt work. From a worker standpoint, accidents that result in injury can lead to mental anguish, possible loss of earnings, and disruption of the work routine. The two basic causes of accidents are worker carelessness and accident hazards. Under the heading of carelessness come unsafe acts. Examples include failing to use protective equipment, overriding safety controls (e.g., taping control buttons down), disregarding safety Ethical Issues. Ethical issues affect operations through work methods, working conditions and employee safety, accurate record keeping, unbiased performance appraisals, fair compensation,and opportunities for advancement. Compensation Compensation is a significant issue for the design of work systems. It is important for organizations to develop suitable compensation plans for their employees. If wages are too low, organizations may find it difficult to attract and hold competent workers and managers. If wages are too high, the increased costs may result in lower profits, or may force the organization to increase its prices, which might adversely affect demand for the organization's products or services. Organizations use a variety of approaches to compensate employees, including time-based systems, output-based systems, and knowledge-based systems. [***Time-based systems***,] also known as hourly and measured daywork systems, compensate employees for the time the employee has worked during a pay period. Salaried workers also represent a form of time-based compensation. ***[Output-based (incentive]**)* systems compensate employees according to the amount of output they produce during a pay period, thereby tying pay directly to performance. Time-based systems are more widely used than incentive systems, particularly for office, administrative, and managerial employees, but also for blue-collar workers. One reason for this is that computation of wages is straightforward and managers can readily estimate labor costs for a given employee level. Employees often prefer time-based systems because the pay is steady and they know how much compensation they will receive for each pay period. In addition, employees may resent the pressures of an output-based system. Another reason for using time-based systems is that many jobs do not lend themselves to the use of incentives. In some cases, it may be difficult or impossible to measure output. For example, jobs that require creative or mental work cannot be easily measured on an output basis. Other jobs may include irregular activities or have so many different forms of output that measuring output and determining pay are fairly complex. On the other hand, situations exist where incentives are desirable. Incentives reward workers for their output, presumably causing some workers to produce more than they might under a time-based system. The advantage is that certain (fixed) costs do not vary with increases in output, so the overall cost per unit decreases if output increases. Workers may prefer incentive systems because they see a relationship between their efforts and their pay: An incentive system presents an opportunity for them to earn more money. On the negative side, incentive systems involve a considerable amount of paperwork, computation of wages is more difficult than under time-based systems, output has to be measured and standards set, cost-of-living increases are difficult to incorporate into incentive plans, and contingency arrangements for unavoidable delays have to be developed. ***Individual Incentive Plans***. Individual incentive plans take a variety of forms. The simplest plan is straight piecework. Under this plan, a worker's pay is a direct linear function of his or her output. In the past, piecework plans were fairly popular. Now minimum wage legislation makes them somewhat impractical. Even so, many of the plans currently in use represent variations of the straight piecework plan. They typically incorporate a base rate that serves as a floor: Workers are guaranteed that amount as a minimum, regardless of output. The base rate is tied to an output standard; a worker who produces less than the standard will be paid at the base rate. This protects workers from pay loss due to delays, breakdowns, and similar problems. In most cases, incentives are paid for output above standard, and the pay is referred to as a bonus. ***Group Incentive Plans***. A variety of group incentive plans, which stress sharing of productivity gains with employees, are in use. Some focus exclusively on output, while others reward employees for output and for reductions in material and other costs. One form of group incentive is the team approach, which many companies are now using for problem solving and continuous improvement. The emphasis is on team, not individual, performance. **Knowledge-Based Pay Systems.**. As companies shift toward lean production, a number of changes have had a direct impact on the work environment. One is that many of the buffers that previously existed are gone. Another is that fewer managers are present. Still another is increased emphasis on quality, productivity, and flexibility. Consequently, workers who can perform a variety of tasks are particularly valuable. Organizations are increasingly recognizing this, and they are setting up pay systems to reward workers who undergo training that increases their skill levels. This is sometimes referred to as knowledge-based pay. It is a portion of a worker's pay that is based on the knowledge and skill that the worker possesses. Knowledge-based pay has three dimensions: Horizontal skills reflect the variety of tasks the worker is capable of performing; vertical skills reflect managerial tasks the worker is capable of; and depth skills reflect quality and productivity results. Management Compensation. Many organizations that traditionally rewarded managers and senior executives on the basis of output are now seriously reconsidering that approach. With the new emphasis on customer service and quality, reward systems are being restructured to reflect new dimensions of performance. In addition, executive pay in many companies is being more closely tied to the success of the company or division that the executive is responsible for. Even so, there have been news reports of companies increasing the compensation of top executives even as workers were being laid off and the company was losing large amounts of money! Recent Trends. Many organizations are moving toward compensation systems that emphasize flexibility and performance objectives, with variable pay based on performance. Some are using profit-sharing plans, or bonuses based on achieving profit or cost goals. In addition, the increasing cost of employee health benefits is causing organizations to rethink their overall compensation packages. Some are placing more emphasis on quality of work life. An ideal compensation package is one that balances motivation, profitability, and retention of good employees. **7.4 METHODS ANALYSIS** Methods analysis focuses on how a job is done. Job design often begins with an analysis of the overall operation. It then moves from general to specific details of the job, concentrating on arrangement of the workplace and movements of materials and/or workers. Methods analysis can also be a good source of productivity improvements The need for methods analysis can come from a number of different sources: Changes in tools and equipment, changes in product design or introduction of new products, changes in materials or procedures, government regulations or contractual agreements, and incidents such as accidents and quality problems. Methods analysis is done for both existing jobs and new jobs. For a new job, it is needed to establish a method. For an existing job, the procedure usually is to have the analyst observe the job as it is currently being performed and then devise improvements. For a new job, the analyst must rely on a job description and an ability to visualize the operation. The basic procedure in methods analysis is as follows: 1\. Identify the operation to be studied, and gather all pertinent facts about tools, equipment, materials, and so on. 2\. For existing jobs, discuss the job with the operator and supervisor to get their input. 3\. Study and document the present method of an existing job using process charts. For new jobs, develop charts based on information about the activities involved. 4\. Analyze the job. 5\. Propose new methods. 6\. Install the new methods. 7\. Follow up implementation to assure that improvements have been achieved. **Selecting an Operation to Study.** Sometimes a foreman or supervisor will request that a certain operation be studied. At other times, methods analysis will be part of an overall program to increase productivity and reduce costs. Some general guidelines for selecting a job to study are to consider jobs that: Have a high labor content Are done frequently Are unsafe, tiring, unpleasant, and/or noisy Are designated as problems (e.g., quality problems, processing bottlenecks) **Documenting the Current Method**. Use charts, graphs, and verbal descriptions of the way the job is now being performed. This will provide a clear understanding of the job and serve as a basis of comparison against which revisions can be judged. Analyzing the Job and Proposing New Methods. Job analysis requires careful thought about the what, why, when, where, and who of the job. Often, simply going through these questions will clarify the review process by encouraging the analyst to take a devil's advocate attitude toward both present and proposed methods. Analyzing and improving methods is facilitated by the use of various charts such as flow process charts and worker-machine charts. *[Flow process charts]* are used to review and critically examine the overall sequence of an operation by focusing on the movements of the operator or the flow of materials. These charts are helpful in identifying nonproductive parts of the process (e.g., delays, temporary storages, distances traveled). Figure 7.3 describes the symbols used in constructing a flow process chart, and Figure 7.4 illustrates a flow process chart. The uses for flow process charts include studying the flow of material through a department, studying the sequence that documents or forms take, analyzing the movement and care of surgical patients, studying the layout of department and grocery stores, and handling mail. Experienced analysts usually develop a checklist of questions they ask themselves to generate ideas for improvements. The following are some representative questions: Why is there a delay or storage at this point? How can travel distances be shortened or avoided? Can materials handling be reduced? **FIGURE 7.4 -\>** Format of a flow process chart **Installing the Improved Method.** Successful implementation of proposed method changes requires convincing management of the desirability of the new method and obtaining the cooperation of workers. If workers have been consulted throughout the process and have made suggestions that are incorporated in the proposed changes, this part of the task will be considerably easier than if the analyst has assumed sole responsibility for the development of the proposal. If the proposed method constitutes a major change from the way the job has been performed in the past, workers may have to undergo a certain amount of retraining, and full implementation may take some time to achieve. **The Follow-Up**. In order to ensure that changes have been made and that the proposed method is functioning as expected, the analyst should review the operation after a reasonable period and consult again with the operator. **7.5 MOTION STUDY** **Motion study is the systematic study of the human motions used to perform an operation.** **The purpose is to eliminate unnecessary motions and to identify the best sequence of motions** **for maximum efficiency. Hence, motion study can be an important avenue for productivity** **improvements. Present practice evolved from the work of Frank Gilbreth, who originated the** **concepts in the bricklaying trade in the early 20th century. Through the use of motion study** **techniques, Gilbreth is generally credited with increasing the average number of bricks laid** **per hour by a factor of 3, even though he was not a bricklayer by trade. When you stop to** **realize that bricklaying had been carried on for centuries, Gilbreth's accomplishment is even** **more remarkable.** **There are a number of different techniques that motion study analysts can use to develop** **efficient procedures. The most-used techniques are the following:** ** Motion study principles** ** Analysis of therbligs** ** Micromotion study** ** Charts** **Gilbreth's work laid the foundation for the development of motion study principles, which** **are guidelines for designing motion-efficient work procedures. The guidelines are divided** **into three categories: principles for use of the body, principles for arrangement of the workplace,** **and principles for the design of tools and equipment. Table 7.3 lists some examples of** **the principles.** **In developing work methods that are motion efficient, the analyst tries to:** ** Eliminate unnecessary motions** ** Combine activities** ** Reduce fatigue** ** Improve the arrangement of the workplace** ** Improve the design of tools and equipment** **Therbligs are basic elemental motions. The term therblig is Gilbreth spelled backward** **(except for the th). The approach is to break jobs down into basic elements and base** **improvements on an analysis of these basic elements by eliminating, combining, or rearranging** **them.** Although a complete description of [therbligs] is outside the scope of this text, a list of some common ones will illustrate the nature of these basic elemental motions: **Search** implies hunting for an item with the hands and/or the eyes. **Select** means to choose from a group of objects. **Grasp** means to take hold of an object. **Hold** refers to retention of an object after it has been grasped. **Transport** load means movement of an object after hold. **Release** load means to deposit the object. Some other therbligs are inspect, position, plan, rest, and delay. Describing a job using therbligs often takes a substantial amount of work. However, for short, repetitive jobs, therbligs analysis may be justified. Frank Gilbreth and his wife, Lillian, an industrial psychologist, were also responsible for introducing motion pictures for studying motions, called micromotion study. This approach is applied not only in industry but also in many other areas of human endeavor, such as sports and health care. Use of the camera and slow-motion replay enables analysts to study motions that would otherwise be too rapid to see. **7.6 WORK MEASUREMENT** Job design determines the content of a job, and methods analysis determines how a job is to be performed. Work measurement is concerned with determining the length of time it should take to complete the job. Job times are vital inputs for capacity planning, workforce planning, estimating labor costs, scheduling, budgeting, and designing incentive systems. Moreover, from the workers' standpoint, time standards reflect the amount of time it should take to do a given job working under typical conditions. The standards include expected activity time plus allowances for probable delays. A standard time is the amount of time it should take a qualified worker to complete a specified task, working at a sustainable rate, using given methods, tools and equipment, raw material inputs, and workplace arrangement. Whenever a time standard is developed for a job, it is essential to provide a complete description of the parameters of the job because the actual time to do the job is sensitive to all of these factors; changes in any one of the factors can materially affect time requirements. For instance, changes in product design or changes in job performance brought about by a methods study should trigger a new time study to update the standard time. As a practical matter, though, minor changes are occasionally made that do not justify the expense of restudying the job. Consequently, the standards for many jobs may be slightly inaccurate. Periodic time studies may be used to update the standards. Organizations develop time standards in a number of different ways. Although some small manufacturers and service organizations rely on subjective estimates of job times, the most commonly used methods of work measurement are (1) stopwatch time study, (2) historical times, (3) predetermined data, and (4) work sampling. The following pages describe each of these techniques in some detail. **Stopwatch Time Study** Stopwatch time study was first introduced over a hundred years ago by Frederick Winslow Taylor to set times for manufacturing and construction activities. It was met with much resistance from workers, who felt they were being taken advantage of. Nonetheless, over time, this measurement tool gained acceptance, and it is now a common practice to conduct time studies on a wide range of activities in distribution and warehousing, janitorial services, waste management, call centers, hospitals, data processing, retail operations, sales, and service and repair operations. It is especially appropriate for short, repetitive tasks. **Stopwatch time study** is used to develop a time standard based on observations of one worker taken over a number of cycles. That is then applied to the work of all others in the organization who perform the same task. The basic steps in a time study are the following: 1\. Define the task to be studied, and inform the worker who will be studied. 2\. Determine the number of cycles to observe. 3\. Time the job and rate the worker's performance. 4\. Compute the standard time. **[Observed Time]**. The observed time is simply the average of the recorded times. Thus, **[Normal Time].** The normal time is the observed time adjusted for worker performance. It is computed by multiplying the observed time by a performance rating. That is, **NT = OT × PR** **[Standard Time].** The normal time does not take into account such factors as personal delays (worker fatigue, getting a drink of water or going to the restroom), unavoidable delays (machine adjustments and repairs, talking to a supervisor, waiting for materials), or breaks. The standard time for a job is the normal time multiplied by an allowance factor for these delays. The standard time is **ST = NT × AF** **Standard Elemental Times** **Standard elemental times are derived from a firm's own historical time study data. Over the** **years, a time study department can accumulate a file of elemental times that are common to** **many jobs. After a while, many elemental times can be simply retrieved from the file, eliminating** **the need for analysts to go through a complete time study to obtain them.** **The procedure for using standard elemental times consists of the following steps:** **1. Analyze the job to identify the standard elements.** **2. Check the file for elements that have historical times, and record them. Use time study** **to obtain others, if necessary.** **3. Modify the file times if necessary (explained as follows).** **4. Sum the elemental times to obtain the normal time, and factor in allowances to obtain** **the standard time.** **Predetermined Time Standards** **Predetermined time standards involve the use of published data on standard elemental** **times. A commonly used system is methods-time measurement (MTM), which was developed** **by the Methods Engineering Council. The MTM tables are based on extensive research of** **basic elemental motions and times. To use this approach, the analyst must divide the job into** **its basic elements (reach, move, turn, disengage), measure the distances involved** (if applicable**),** **rate the difficulty of the element, and then refer to the appropriate table of data to obtain** **the time for that element. The standard time for the job is obtained by adding the times for all** **of the basic elements. One minute of work may cover quite a few basic elements; a typical job** **may involve several hundred or more of these basic elements. The analyst needs a considerable** **amount of skill to adequately describe the operation and develop realistic time estimates.** **Analysts generally take training or certification courses to develop the necessary skills to do** **this kind of work.** **Among the advantages of predetermined time standards are the following:** ** They are based on large numbers of workers under controlled conditions.** ** The analyst is not required to rate performance in developing the standard.** ** There is no disruption of the operation.** ** Standards can be established even before a job is done.** **Work Sampling** **Work sampling is a technique for estimating the proportion of time that a worker or machine** **spends on various activities and in idle time.** **Unlike time study, work sampling does not require timing an activity, nor does it even** **involve continuous observation of the activity. Instead, an observer makes brief observations** **of a worker or machine at random intervals and simply notes the nature of the activity. For** **example, a machine may be busy or idle; a secretary may be typing, filing, talking on the** **telephone, and so on; and a carpenter may be carrying supplies, taking measurements, cutting** **wood, and so on. The resulting data are counts of the number of times each category of activity** **or nonactivity was observed.** **Although work sampling is occasionally used to set time standards, its two primary uses** **are in (1) ratio-delay studies, which concern the percentage of a worker's time that involves** **unavoidable delays or the proportion of time a machine is idle, and (2) analysis of nonrepetitive** **jobs. In a ratio-delay study, a hospital administrator, for example, might want to estimate** **the percentage of time that a certain piece of X-ray equipment is not in use. In a nonrepetitive** **job, such as secretarial work or maintenance, it can be important to establish the percentage of** **time an employee spends doing various tasks.** **Nonrepetitive jobs typically involve a broader range of skills than repetitive jobs, and** **workers in these jobs are often paid on the basis of the highest skill involved. Therefore, it is** **important to determine the proportion of time spent on the high-skill level. For example, a secretary may do word processing, file, answer the telephone, and do other routine office work.** **If the secretary spends a high percentage of time filing instead of doing word processing, the** **compensation will be lower than for a secretary who spends a high percentage of time doing** **word processing. Work sampling can be used to verify those percentages and can therefore be** **an important tool in developing the job description. In addition, work sampling can be part of** **a program for validation of job content that is needed for "bona fide occupational qualifications"---** **that is, advertised jobs requiring the skills that are specified.** **Work sampling estimates include some degree of error. Hence, it is important to treat work** **sampling estimates as approximations of the actual proportion of time devoted to a given** **activity. The goal of work sampling is to obtain an estimate that provides a specified confidence** **of not differing from the true value by more than a specified error. For example, a hospital** **administrator might request an estimate of X-ray idle time that will provide a 95 percent** **confidence of being within 4 percent of the actual percentage. Hence, work sampling is** **designed to produce a value, p \^, which estimates the true proportion, p, within some allowable** **error, e : p\^   ± e. The variability associated with sample estimates of p tends to be approximately** **normal for large sample sizes. The amount of maximum probable error is a function of both** **the sample size and the desired level of confidence.** **For large samples, the maximum error percent e can be computed using the following** **formula:**