Table 5.17 lists ten key steps that will help an organization simplify its work. These are broadly divided into the three categories of (1) not creating the work in the first place, (2) efficiently doing work that must be done, and (3) standardization of the work so it is done the same way every time regardless of the person doing it. Work simplification begins in the product or service design phase. This is the first step in Table 5.17, which states, “Simplify the product or service design first.” The fewer the components or assembly operations a design has, the less work that will be required to produce it day to day. This concept is embodied in the design
table 5.17 10 key Steps to Simplify and Standardize Work
1. Simplify the product or service design first.
2. Design the process as simply as possible using automatic systems where practical to minimize the percentage of manual activities, and mistake- proof the process.
3. Balance workflow between operations based on the required takt time (time allowed to produce one unit). This will be discussed in Chapter 6. 4. Break the work of each operation into its elemental tasks either
empirically through observation and work sampling or micromotion study, or using predetermined time standards.
5. Set time standards by work task within each operation.
6. Develop a sequential strategy to do the work tasks the “best way” to minimize time and unnecessary motions using tools, methods, and fixtures that will mistake-proof the work.
7. Ensure work tasks are combined or broken into parallel activities that will not exceed the takt time.
8. Ensure work procedures are standardized, easy to understand, and visual in nature with examples of good and poor workmanship.
9. Ensure people are trained to perform, measure, and continuously improve their workmanship.
for manufacturing (DFM) concepts listed in Table 4.7. The second key step of Table 5.17 recommends simple automation and mistake-proofing of work opera- tions to minimize the percentage of manual activities within a process workflow. This will reduce the direct labor requirements necessary to produce a product or service and reduce errors. Once the required operational sequences have been determined by process engineering, the flow of work across the work operations is balanced according to the system’s takt time — the time allowed to produce one unit. An example would be having a production schedule of 80 units and 8 hours (480 minutes) of available manufacturing time. This would require a takt time of one unit every six minutes throughout the eight-hour shift. Takt time and other Lean tools, methods, and concepts will be discussed in Chapter 6. Once the takt time has been calculated, the sequence of work tasks within each operation is aggregated or formed into operations or workstations consisting of one or more work tasks. The cumulative completion time of all work tasks, within an operation, must be less than or equal to the system’s takt time. In other words, if the takt time is one unit every six minutes, then the maximum cycle time for every operation or workstation must be six minutes or less. To achieve this takt time, work tasks may be aggregated together or broken into smaller groups, as shown in Figure 5.16. To do this, the work tasks must be studied to determine the best way and time to complete each work task. Common methods for studying work tasks are work sampling, micromotion studies, or predetermined time standards. Work sampling involves studying a work task over a period of time and determining the best way to accomplish the task. Micro motion studies are similar to work sampling, but are more precise in determining work task time duration than simple work sam- pling methods. This is because cameras are used to record every motion related to completing the work task. This allows the motions associated with a work task to be studied over and over. Also, time duration can be measured to a microsecond level of precision. Predetermined time standards can be applied up front to a new workflow design and later validated through work sampling or micromotion stud- ies. Alternatively, they can be created using these methods. Time standards are used to design the manual portion of new process workflows, and with similar analyses of machine cycle times to balance the flow of work across the process workflow to achieve the required takt time.
Figure 5.17 shows how data from more detailed time and motion studies can be summarized to determine what major components of time are allowed within a process. A baseline analysis is conducted of an operation’s work tasks, and the time required to complete each task is calculated but at a work task level of detail. An analysis is made of each work task and its time duration to identify and elimi- nate wasted time elements. Next, time standards are calculated for each work task, similar to the standard method shown in Figure 5.17. This data collection form also enables collection of time durations that are related to the use of specific tools, materials, and fixtures. The tasks are further categorized as setting up a job, inspect- ing the work, actually doing the work, moving the work, or waiting for materials
Using Lean Methods to Design for Process Excellence n 163 System Process 2 Workflow 2 Process 1 Workflow 1 Operation 1 Work Task 1 Micro-Motion 1 Operation 2 Work Task 2 Micro-Motion 2 Process h Workflow l Operation j Work Task k Micro-Motion I
figure 5.16 how to identify lower-level work tasks.
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or information. As part of this analysis, unnecessary work tasks are eliminated and the remaining work tasks are mistake-proofed. Finally, employees who actually do the work are trained on how to use the new work methods, tools, and inspection and measurement systems. Visual examples of good and poor workmanship are also frequently used to control and improve work methods.