Work measurement is the careful analysis of a task, its size, the method used in its performance, and its efficiency. The objective is to determine the workload in an operation, the time that is required, and the number of workers needed to perform the work efficiently. Work measurement helps to determine the time spent performing any process and offers a consistent, comparable methodology for establishing labor capacities.
Work measurement can be extremely effective at informing supervisors of the working times and delays inherent in different ways of carrying out work. The purpose of a measurement method is to achieve full coverage of the work to be measured.
A good work measurement system has many benefits. It helps to reduce labor costs, increase productivity, and improve supervision, planning, scheduling, performance appraisal, and decision making.
WORK MEASUREMENT COMPONENTS
A work measurement system has three components: preferred methods, time values, and reporting. Preferred methods are not always the most efficient or fastest way to do a task. They should enhance safety, quality, and productivity. Safety for the employee and for the product should be considered. Quality is equally important; it has been proven that good performance and good quality go hand in hand. People who are trained in the proper method and follow that method will produce high-quality work and perform at an acceptable performance level. Time values and reporting should also be considered. The time that a job should take is determined not on the basis of speeding up the motions a worker normally makes but on the normal pace of the average worker, taking into consideration allowances for rest periods, coffee breaks, and fatigue. A reporting system is important to the success of any work measurement method. Supervisors and managers must have access to labor-management information that is both timely and complete. Timely information can be used to manage and shift labor hours to areas where they are needed and to correct problems or at least prevent them from becoming a crisis. Personal computers help to apply work measurement more effectively and more cheaply and provide immediate feedback to the workers, supervisors, and managers.
WORK MEASUREMENT METHODS
Work measurement programs involve the use of a number of techniques, each selected to cover an appropriate part of the task. The purpose of measurement is to collect real data about actual events. To obtain time standards, the data are usually converted to target data or data that apply under known conditions. All work measurement systems are based on the same, simple three-stage procedure: analysis, data collection and measurement, and synthesis. They differ in the nature and degree of analysis, the nature and level of data collection and measurement, and the nature of the synthesis process. However, the three-stage procedure remains common.
Before measurement begins, the task to be measured is analyzed and broken into convenient parts that are suitable for the chosen measurement technique. The purpose of the measurement technique is to derive a basic time for each activity, element, or motion. At the measurement stage, it is necessary to collect descriptive or qualitative data on the nature of the task, the conditions under which it is performed, and other factors, which may have a bearing on the time that the task takes to be complete. When repetitive jobs are measured, data are collected over a number of representative cycles of a job to obtain a mean or typical value. An analysis of the results can be done using statistical techniques to determine the number of observations that must be made to provide a given level of confidence in the final results.
At the synthesis stage, the various parts of the task and their associated basic times are combined together in correct sequence and with the correct frequency to produce the time for a complete job. During this stage, the basic time will be adjusted for allowances to become the standard time for the task.
There are four work measurement methods, each of which has strengths and weaknesses. The historical data method shows the time it actually took to complete a task. Such data have the advantages of being easy to collect, understand, and communicate, but they provide no information for future improvement. For the work sampling method, a large number of random observations are made of the task to determine the steps in its normal performance. This method is easy to learn and use, and it provides more operational detail than historical data. The disadvantage of work sampling is that it requires thousands of samples to establish an accurate measure for each step.
The time study method uses continuous and snapback approaches to record the elapsed time of a task. The snapback approach requires a stopwatch with a reset button that allows the observer to read and record the time at the end of each work element then reset (snapback) the watch to zero. Although popular, the time-study method is subjective and relies heavily on the experience of the time-study analyst. A computerized data collector provides more accurate timing than the stopwatch. However, converting actual time to the expected or normal time remains a problem.
The predetermined motion/time systems method is based on the premises that all work consists of basic human motions and that times can be assigned to these motions if they are defined and classified in a systematic way. A film or videotape records what a job entails and how long it takes. This technique is used most frequently in studying high-volume settings such as a workstation or an assembly line. An observer measures a job by watching and analyzing it into its basic constituent motions. This method requires substantial training and practice to acquire and maintain accuracy. It enables all types of tasks to be assigned time/duration values that can then be extended into cost values. The results are not easy to communicate, but when properly executed, this method yields very accurate times.
see also Productivity ; Standard-Based Work Performance
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