Exam 7: Work Design and Measurement

A work sampling study is needed that will estimate the percentage of time a postal clerk spends selling stamps as opposed to other duties. Determine the necessary sample size to estimate that proportion with a confidence of 99.74 percent to within 3 percent, for these cases: (1) No information is currently available concerning that proportion. (2) The proportion is probably no more than 15 percent.

The normal time in time study is obtained by multiplying the observed time by the performance rating.

Work sampling provides both quick and accurate estimates of activity times.

Standard times derived from a firm's historical data are known as:

A flow process chart is helpful for visualizing the portions of a work cycle during which the operator and equipment are busy or idle.

We incorporate the average seriousness of accidents by measuring the number of lost-time accidents per million labor hours worked.

A methods and measurement analyst wants to develop a time standard for a certain task. In a preliminary study, he observed one worker perform the task six times with an average observed time of 20 seconds and a standard deviation of two seconds. How many observations should be made if he wants to be 95.44 percent confident that the maximum error in the observed time is one second?

The manager of Lawn and Garden Services would like to estimate the proportion of her employees' time spent performing various gardening and lawn care activities. She has made 400 random observations of a typical worker, with the following results: Activity Times Observed Mowing 200 Trimming 80 Raking 40 Miscellaneous 80 If the manager wants to be 95.44 percent confident that the true proportion of time spent mowing is within .02 (plus or minus) of the sample proportion, what should be her sample size?

Determining the number of cycles to observe is an element of:

Work sampling can be used to estimate the proportion of time a machine is idle.

A methods and measurements analyst for Digital Devices needs to develop a time standard for the task of assembling a computer mouse. In a preliminary study, she observed one of her workers perform this task six times with the following results: Observation 1 2 3 4 5 6 Time (seconds) 46 38 40 34 42 40 What is the normal time for this task if the employee worked at a 20 percent faster pace than average?

The design of work systems, because objective standards are used, avoids most ethical issues.

A methods and measurements analyst for Digital Devices needs to develop a time standard for the task of assembling a computer mouse. In a preliminary study, she observed one of her workers perform this task six times with the following results: Observation 1 2 3 4 5 6 Time (seconds) 46 38 40 34 42 40 How many observations should be made if she wants to be 86.64 percent confident that the maximum error in the observed time is .5 second? Assume that the standard deviation of the task time is four seconds.

Which of the following is not a potential benefit of the use of self-directed teams?

A work sampling study of dockworkers must be set up. There will be a large number of random observations. However, for this exercise, determine an observation schedule (arranged chronologically) for six observations. Assume workers are on the docks for eight hours a day, and that the study will be done over a 60-day period. Use the random digits listed below. Day 81 22 53 94 95 96 17 28 39 70 61 12 43 04 25 86 27 28 19 Hour 1 3 9 6 7 3 5 4 3 2 4 9 7 7 1 3 2 5 8 Minute 03 19 25 70 81 93 02 18 27 33 44 53 05 10 28 33 41 53 66

No stopwatch is required in a work sampling study.

Self-directed teams help other work groups make changes to their processes.

A job had an observed cycle time of four minutes, a performance rating of 80 percent, and an allowance factor that was 20 percent of job time. Normal time for the job in minutes is:

In methods analysis, a therblig is a:

The normal time for a job is multiplied by the performance rating to obtain the standard time for the job.