A common practice in manufacturing and other nonservice lean initiatives is the application of work cells for supporting workflow and productivity. Work cells enable maximum efficiency of workflow through a value stream by optimizing motion economy. One tool for efficient work cell design is a predetermined time system. Although these are used frequently in nonservice industries, they are also available, although applied much less frequently, for administrative work environments.

Administrative predetermined time systems

An administrative predetermined time system is comprised of engineered (i.e., derived from rigorous study) time values for performing work actions in administrative work industries (e.g., banking, insurance, government) and operations (accounts payable, application processing, claims processing). Comprehensive administrative predetermined time systems include data for performing the administrative actions listed in figure 1:

Figure 1: Administrative actions whose data are included in administrative predetermined time systems

Time values in predetermined time systems represent the expected performance rate of the average, fully-trained worker working without interruptions. Normal interruptions (e.g., getting supplies, getting a cup of coffee, short conversations with co-workers) are accounted for by applying a miscellaneous work interruption allowance. Most administrative predetermined time systems incorporate a 10 percent to 15 percent miscellaneous work interruption, increasing the basic time for performing an administrative activity to allow for minor work interruptions throughout the work day.

All of today’s major administrative predetermined time systems are based upon methods-time measurement, the most widely used predetermined time system in the world. Methods-time measurement is deployable in both services and nonservices work environments. The technique was developed during the 1940s by Harold Maynard, Gustave Stegemerten, and John Schwab at Westinghouse Electric Corp. in response to a need for greater accuracy and consistency in time studies, and greater effectiveness in methods analysis and improvement.

Because of the detailed nature of methods-time measurement (e.g., time required to reach ¾ in. or less for an object whose location may vary slightly from cycle to cycle = 0.0719 seconds), a new unit of time was developed. The time unit used in methods-time measurement is known as the time measurement unit, or TMU. Time measurement units are directly convertible to our normal time system of seconds, minutes, and hours, as illustrated in figure 2.

Figure 2: A second, a minute, and an hour converted to time measurement units

Basic methods-time measurement (aka MTM 1) is used for developing administrative predetermined time systems by first defining a common administrative action and then applying the MTM 1 data system to construct the time required to perform the action. Figure 3 shows the development of a time value for a common administrative action: stapling papers using a desk stapler.

Figure 3: The development of a time value for stapling papers using a desk stapler

A lean Six Sigma Green or Black Belt trained in using an administrative predetermined time system would only have to observe and document that the action (stapling papers) is taking place and assign its appropriate code and time value, thus ensuring that time accuracy is retained but eliminating the need to conduct a time-consuming basic motion/time analysis. See figure 4.

Figure 4: Documentation that stapling papers was done and took 40 time measurement units

Time values in an administrative predetermined time system reflect performing a specific action one time so that a frequency study is necessary for determining the required time to perform a specific administrative activity. Figure 5 shows an example of an administrative predetermined time system for entering credit report requests.

Figure 5: An administrative predetermined time system for entering credit report requests (includes a 10% miscellaneous work interruption allowance).

With the current state (Total c) activity measured, an administrative lean team can now begin to develop a work cell concept and identify where worker actions and related times can be reduced to create a more efficient work cell layout and workflow.

Creating a work cell concept and detailed design

The administrative lean team can develop a work cell concept by taking the following steps:
1. Identify the ideal sequence of work activities for the value stream.
2. Start with a “straight line” work-cell concept layout to ensure unidirectional workflow, as illustrated in figure 6.

Figure 6: A straight line work-cell concept layout

Once a work cell concept is developed, an administrative lean team can start to build a detailed work cell design by taking these steps:
3. Identify where work queues (i.e., backlogs) develop in the workflow.
4. Identify approaches for eliminating or significantly reducing work queues (e.g., single-piece flow, small batch flow, line balancing, work in progress CAP)
5. Identify opportunities for motion economy.

Using an administrative predetermined time system, there are three strategies for motion economy:
1. Eliminate (E) the action.
2. Reduce (R) the frequency of the action.
3. Substitute (S) a less time-consuming action.

U-shaped work cells (see figure 7) are commonly used to optimize administrative value stream motion economy.

Figure 7: U-shaped work cells

Figure 8 shows the effect of applying motion economy strategies to our sample administrative activity.

Figure 8: The effect of applying motion economy strategies to entering credit report requests, which was the administrative activity in figure 5 (includes a 10% miscellaneous work interruption allowance).

The activity in figure 8 shows that applying strategies for reducing worker motion (eliminate, reduce, substitute) has resulted in a 20-percent (18.5 sec per request to 14.8 sec per request) action/time reduction. For example, a reduction in the distance the data entry associate must make for delivering completed work batches to the quality assurance analyst resulted in an action time savings of 21.5 sec (from 60 total paces to 20 total paces = 40 paces reduced × 15 TMU per pace/27.8 TMU per sec = 21.5 sec) for each work batch. The Total f column reflects the future state action/time values for this activity.

In actual implementation, the administrative lean team would continue to apply the administrative predetermined time system to each additional administrative activity to maximize overall value-stream motion economy.

Once a detailed work cell design has been planned, it should be piloted and fine-tuned to maximize its efficiency. As new work activities are added to the value stream, methods for maximizing their efficiency can be analyzed and selected prior to their actual implementation by using an administrative predetermined time system.

Conclusion

Work cell design offers administrative work environments a significant opportunity for reducing the cycle time, lead time, and cost of administrative value streams. An administrative predetermined time system can be a powerful tool for optimizing administrative work cell design. An administrative predetermined time system offers administrative lean practitioners many advantages, including:
• Providing a detailed analysis of administrative work methods
• Providing extremely accurate administrative activity time values
• Providing highly consistent time values for administrative work activities (i.e., high repeatability, high reproducibility)
• Allowing for administrative work methods to be tested in advance of implementation
• Eliminating the need for stopwatch measurement of administrative workers
• Optimizing administrative workflow and work cell design