Work Measurement Studies
Work Measurement Studies
Work Measurement Study is a general term used to describe the systematic application of industrial engineering techniques to establish the work content and time it should take to complete a task or series of tasks.
Work measurement is a productivity improvement tool. Before improvements can be made, the current productivity level of an organization must be measured. This measurement is then used as a baseline to determine if improvement projects have resulted in genuine improvement.
Work measurement helps to uncover non-value added areas of waste, inconsistency, and non-standardization that exist in the workplace. Work measurement studies uncover ways to make work easier, and to produce products or services more quickly and economically.
Work is measured for four reasons:
- To discover and eliminate lost or ineffective time.
- To establish standard times for performance measurement.
- To measure performance against realistic expectations.
- To set operating goals and objectives.
Work measurement involves the use of engineered labor standards to measure and control the amount of time required to perform a specific task or tasks. While labor standards are most commonly associated with manufacturing or production environments, standards are used in many other types of settings including, but not limited to:
- service or administrative,
- warehousing and distribution,
- medical and utilities.
Work Measurement Techniques
Under the work measurement umbrella there are a number of techniques for collecting the information necessary to develop engineered labor standards.
Time Study is the most widely used work measurement technique that employs a decimal minute stopwatch to record and determine the time required by a qualified and well-trained person working at a normal pace to do a specific task under specified conditions. The result of the time study is the time that a person suited to the job and fully trained in the specified method will need to perform the job if they work at a normal or standard pace.
Predetermined Time Systems are a technique of motion study and time standards development. The motions of the work or task performed are recorded. Each basic motion has a time value associated with it. Once all the motions for the task have been recorded, the time values are totaled and the standard time for the operation is developed.
Standard Time Data (Standard Data) is a generic term given to a collection of time values. Standard data uses work elements from time studies or other work measurement sources making it unnecessary to restudy work elements that have been timed adequately in the past. These element times are extracted from studies and applied to jobs or tasks with the same element(s). Some examples of standard data development include graphs, tables, charts, formulas and spreadsheet programs.
Work Sampling is a random sampling technique (statistical sampling theory) that involves observing the worker(s) at randomly selected times and recording the type of activity that is observed at that instance. Work sampling is most commonly used to collect information for allowance calculation, to determine the distribution of work activities, and to determine the productive and non-productive utilization of workers.
Work sampling is based on the theory that the percentage of the number of observations on a particular activity is a reliable measure of the percentage of the total actual time spent on that activity. Work sampling operates by an observer taking a series of random observations on a particular "thing" of interest (machine, operating room, dock, etc.) to observe its "state" (working, idle, sleeping, empty, etc.). When enough samples are taken, an analysis of the observations yields a statistically valid indication of the states for each thing analyzed. Assume, for example, that you wish to determine the proportion of time a factory operator is working or idle. Also assume that 200 random observations were made of the operator and during 24 of these he or she was observed to be idle. Therefore, you find that the individual is working 176/200 = 88% of the time.
Advantages of Work Sampling
It is relatively inexpensive to use and extremely helpful in providing a deeper understanding of all types of operations. When properly used, it can help pinpoint those areas, which should be analyzed in, further detail and can serve as a measure of the progress being made in improving operations .
Sample Questions for work sampling study
·What is our equipment/asset utilization?
·When we are not adding value to the product, how are we spending our time?
·How are our inter-dependent systems performing?
·Where should we focus our continuous improvement activities?
Distinction between Work sampling and "Time Studies"
·Work sampling is lower cost because it uses random samples instead of continuous observations.
·Many operators or machines can be studied by a single observer
·Work sampling can span several days or weeks, thus minimizing the effects of day to day load or equipment variations
·Work Sampling tends to minimize operator behavior modification during observation.
·Work Sampling, in general, does not require a trained time-study analyst to take the observations. Also, stopwatches or other timing devices are not required. Many studies make use of off-shift technicians or operators to take the observations.
Work sampling Methodology
An analyst RANDOMLY observes an activity (equipment, operating room, production line) and notes the particular states of the activity at each observation. The ratio of the number of observations of a given state of the activity to the total number of observations taken will approximate the percentage of time that the activity is in that given state. Note that random observations are very critical for a work sampling study. A brief example might be that 77 of 100 observations showed a machine to be running. We might then conclude, within certain statistical limits, that the equipment is operational 77% of the time.