Category Archives: Work Performance Measurement

Worker lnteracting with Equipment

Worker interacting with Equipment

When a person and equipment operate together to perform a given set of tasks, interest focuses on the efficient use of both the person' time and the equipment's time. When the working time of the operator is less than the equipment run time. a worker-machine chart is a useful device in analysis. If the operator can operate several pieces of equipment. the problem is to find the most economical combination of operator and equipment, such that the combined cost of the idle time of the equipment and the idle time for the worker are at a minimum.

Worker-machine charts are always drawn to scale. the scale being time as measured by length. Exhibit S to.S gives an example of a worker-machine chart in a service setting. With many services, however, the "machine" that the worker interacts with is often a computer, which is simultaneously providing and cc'Iecting information (as in the case of making an airline or hotel reservation). In designing these types of processes, the goal is to provide the necessary information as quickly as possible to both the worker and the customer, and also to provide a format for collecting customer data that is both accurate and fast. This is accomplished by having significantly large computer capacity, which is relatively inexpensive in comparison to the cost of the worker.

Worker at a Fixed Workplace

Worker at a Fixed Workplace

There are many jobs that require workers to remain at a specified workstation in order to complete their assigned tasks, This applies to both manufacturing and services. When the nature of the work is primarily manual (such as sorting, inspecting, making entries, or assembly operations l. the focus of work design is on simplifying the work method and making the required operator motions as few and as simple as possible. I The same concepts also apply to services. For example, a customer service representative at a call center is trained to ask specific questions in a given order so that a customer's inquiry is processed as efficiently as possible. With services, however, the issue is further complicated by the presence of the customer in the process. Here efficiency cannot be achieved at the expense of angering the customer, who may perceive an efficient operator as being curt or rude.

There are two basic ways to determine the best method for performing an essentially manual task. The first is to search among the various' workers performing that task and find the one who performs the job best. That person's method is then accepted as the standard, and the other workers are trained to perform it in the same way. This was basically F. W. Taylor's approach, The second method is to observe the performance of a number of workers, analyze in detail each step of their work, and pick out the superior features of each worker's performance, This results in a composite method that combines the best elements of the group studied. This was the procedure used by Frank Gilbreth, the father of motion study, to determine the "one best way" to perform a work task. Taylor observed actual performance

Taylor observed actual performance to find the best method: Frank Gilbreth and his wife Lillian relied on movie film, Through micromotion analysis-observing the filmed work performance frame by frame-the Gilbreths studied work very closely and defined its basic elements. which was termed therbligs ("Gilbreth" spelled backward. with the and posed), The: also used the motion model-a wire representation of the path of a motion. Their study led to the rules or principles of motion economy listed in Exhibit S lOA, Once the various motions for performing a task have been identified, an operations chart is then developed, listing the individual operations and their sequence of performance. For greater detail, a sima (simultaneous motion) chart may be constructed, listing not only the operations but also the times for both left and right hands. This chart may be as enabled from the data collected with a stopwatch, from analysis of a film of the operation. or from predetermined motion-time data (such as that developed by the Gilbreths and discussed later in the chapter), Many aspects of poor design become immediately obvious



with this technique-a hand being used as a holding device (rather than or fixture). an idle hand, or an exceptionally long time for positioning.

Overall Operation

Overall Operation

The objective in studying the overall production system is to identify non-value-added time delays, transport distances, processes and processing time requirements, with the goal of simplifying the entire operation. The primary objective here is to eliminate any step in the process that does not add value to the product. The approach is to develop a process flowchart then ask the question What is done? Must it be done? What would happen if it Were not done?

What is done? Must it be done? What would happen if it ere not done? Where is the task done? it be done at that location or could il be done somewhere else? When i the task done? Is it critical that it be done then or is there flexibility in time and sequence' Could it be done in combination with some other step in the process? How is the task done? Why is it done this way? Is there another way? Who docs the task? Can someone else do it? Should the worker be of a higher or skill level?

These types of questions usually help to eliminate much unnecessary work, as well as the remaining work. by combining a number of processing steps and changing the order of performance. of the process chart is valuable in studying an overall operation, though care must be taken to follow the same item throughout the process, The subject may be a product being manufactured. a service being provided, or a person performing a sequence of activities. An example of a process chart (and flow diagram) for a clerical operation is shown in Exhibit S 10.2. Common notation in process charting is given in Exhibit S 10.3.

Work Performance Measurement

Supplement Objectives

• Introduce the more common types of work methods that are practiced in the workplace.

• Understand the fundamental issues involved in developing work measurements.

• Identify the basic elements associated with conducting a time study.

• Determine how to design a work sampling study and apply it to .an actual operation.

Work needs to be properly designed and measured, regardless of the type of organization in which it is done, be it manufacturing or services. The proper design or' work ensures that tasks are completed with a minimum of wasted effort. Proper work design. as discussed in the previous chapter, also ensures that the work is accomplished without causing injury to the employee.

Work measurement is equally important for several reasons. First. it is used to determine the labor cost, which is usually a major component of the overall cost of producing a good or a service. Second. knowing how long it takes to complete a specific task or assignment provides management with the ability to determine the number of workers needed to meet a given level of demand. For example. the number of customer service representatives that FedEx needs at its call centers is dependent on the demand as expressed in the number of calls it receives daily and the length of time to process each call, which is referred to as the average handling time (AHT). A third reason for work measurement is to identify those workers who are meeting or exceeding standards and who should be appropriately recognized and rewarded.

It also identifies those who fall below the standards and require additional training. In the early part of this century, beginning with Frederick W. Taylor and continuing with Frank and Lillian Gilbreth, work measurements were done almost exclusively in manufacturing companies. While the specific methodology associated with work measurement has basically not changed since its inception with Taylor, the manner in which work measurements are conducted has changed significantly (see OM in Practice: Work Measurement Then and Now).