# Work Design and Measurement

It is important that operations managers are comfortable analyzing business data, and then using the resultant information to make well-informed decisions that will ultimately improve operational efficiency, lower costs, improve “bottom line” performance, and decrease outcome variability that can be attributed to assignable causes. The unit reading will go over the concepts of methods analysis and the measurement of work. First, one employs methods analysis to breakdown a process into basic work tasks. Next, measurement samples are taken of how long it takes to complete each work task. Since there is usually variance in how long it takes workers to complete a task, statistical methods are utilized to estimate the percent of time a worker spends on the task, and how much is idle time. Once the methods analysis is complete, then it is possible to measure the time it takes to complete each work task. Basically you are using quantitative methods to measure work, rather than a subjective qualitative approach.

Unit Learning Outcomes

- Perform descriptive analyses on datasets using Microsoft Excel. (CLO 4, 5, and 7)
- Properly determine standard times for units of work using Microsoft Excel. (CLO 3, 4, and 5)
- Calculate cycle time commonly associated with time studies for production using Microsoft Excel. (CLO 1, 3, 4, 5, and 7)
- Use quantitative data as the basis for making suggested operational improvements within various organizational structures. (CLO 3, 4, and 5)

Directions

End of Chapter Problems (60 points): Answer the following end of chapter problems from the textbook:

Chapter 7 – problems 2, 3, 4, 7, 9, and 11 (pages 332-333, 10 points each).

View the following example videos before working the problems:

https://canvas.park.edu/courses/62827/files/8248197/download?download_frd=1

https://canvas.park.edu/courses/62827/files/8248198/download?download_frd=1

Problems to be answers

- A job was timed for 60 cycles and had an average of 1.2 minutes per piece. The performance rating was 95 percent, and workday allowances are 10 percent. Determine each of the following.
- observed time
- normal time
- standard time

- A time study was conducted on a job that contains four elements. The observed times and performance ratings for six cycles are shown in the following table.

OBSERVATIONS (minutes per cycle) |
|||||||

Element |
PerformanceRating |
1 |
2 |
3 |
4 |
5 |
6 |

1 | 90% | 0.44 | 0.50 | 0.43 | 0.45 | 0.48 | 0.46 |

2 | 85 | 1.50 | 1.54 | 1.47 | 1.51 | 1.49 | 1.52 |

3 | 110 | 0.84 | 0.89 | 0.77 | 0.83 | 0.85 | 0.80 |

4 | 100 | 1.10 | 1.14 | 1.08 | 1.20 | 1.16 | 1.26 |

- Determine the average cycle time for each element.
- Find the normal time for each element.
- Assuming an allowance factor of 15 percent of job time, compute the standard time for this job.

- Given these observed times (in minutes) for four elements of a job, determine the observed time (OT) for each element.
*Note:*The second element only occurs every other cycle.

CYCLE |
||||||

Element |
1 |
2 |
3 |
4 |
5 |
6 |

1 | 4.1 | 4.0 | 4.2 | 4.1 | 4.1 | 4.1 |

2 | — | 1.5 | — | 1.6 | — | 1.4 |

3 | 3.2 | 3.2 | 3.3 | 3.2 | 3.3 | 3.3 |

4 | 2.7 | 2.8 | 2.7 | 2.8 | 2.8 | 2.8 |

- A worker-machine operation was found to involve 3.3 minutes of machine time per cycle in the course of 40 cycles of stopwatch study. The worker’s time averaged 1.9 minutes per cycle, and the worker was given a rating of 120 percent (machine rating is 100 percent). Midway through the study, the worker took a 10-minute rest break. Assuming an allowance factor of 12 percent of work time, determine the standard time for this job.

- The following data were obtained by observing a three-step job of a financial manager’s assistant.
- Using the data and an allowance of 10 percent of job time, determine a standard time for the operation.
- Determine the number of observations that would be required to estimate the mean time for the first element within 4 percent of the true value with a confidence of 98 percent.
- How many observations would be needed to estimate the mean time for element C to within .10 minute of its actual value with a confidence of 90 percent?

OBSERVATIONS (minutes per cycle) |
||||||

Element |
Performance Rating |
1 |
2 |
3 |
4 |
5 |

A | 90% | 1.40 | 1.42 | 1.39 | 1.38 | 1.41 |

B | 120 | 2.10 | 2.05 | 2.00 | 1.85 | 1.80 |

C | 110 | 1.60 | 1.40 | 1.50 | 1.45 | 1.55 |