· Standard vs. Non-Standard Time
Standard work defines the most efficient way to produce a product at a balanced flow to achieve a desired output rate. It is one of the most powerful lean tools that breaks down work into sequenced elements which are repeatedly followed. It also provides a pattern for how a process should consistently be executed and highlights current best practices. This provides a base from which an improved process can be developed, allowing continuous improvement methods to leverage learning. Work measurement is a process of analyzing jobs for the purpose of setting time standards. It is used to schedule work and allocate capacity, motivate and measure work performance, evaluate performance, and provide benchmarks.
Normal time (NT) =Observed performance time per unit x (Performance rating)
The Performance Rating is usually expressed in decimal form in these formulas. So a person working 10% faster than normal would have a Performance Rating of 1.10 or 110% of normal time, working 10% slower, 0.90 or 90% of normal.
Standard time = Normal time/ (1-Allowances)
The Time Study is a technique for calculating the standard time to perform a single element or an operation of elements. This technique has been traditionally used by Industrial Engineers to set standards. Each element combines a number of motions that can be timed. The times measured for those motions serve as a basis for developing standard time.
Establishing standardized work depends on collecting and recording data on various forms. These forms are used by engineers and front-line managers to design the process and by machine operators to make improvements in their jobs. The benefits of standardized work entail documentation of the current process for all shifts, reductions in variability, easier training of new operators, reductions in injuries, and a baseline for improvement activities. Moreover, standardized work supports audits, promotes problem solving, and involves team members in developing poka-yokes.
Toys R Us have been doing time studies for years and determined standard time for most activities. The accepted standard average time of an activity is calculated by adding 10% to the average time it takes to perform it. This 10% that is added for each activity/task accounts for all the unexpected circumstances such as personal fatigue, lateness, delays, etc. The eight categories for which delays have been tracked are: Meeting/Start up, Equipment/RF Failure, Housekeeping, Revisits, Special Projects, Battery Change, Training, and Other. The variance of budgeted hours comparing to the actual hours predetermined for these activities is huge and is dominant in Housekeeping.
The company follows “Clean as you go” principle which means that when cartons slip of the trays or similar accidents occur, they are to be fixed right away. These accidents and all other unexpected circumstances are considered to be Non-Standard time as they cannot be measured since they are unpredictable. However, Non- Standard time should only account for 5% of total time. By looking at the numbers above, one can clearly see the variance to budgeted hours proving Non-Standard time exceeds 5% by far.
The front-line workers sign in at beginning of their shift and sign out in the end. They do not have touch bases with their manager and do not use any timesheets do document their work. The General Manager coordinates managers in four different buildings and is the first person to contact when issues arise. In order to get to the root cause of this issue, the management has to educate the operators about Non-Standard time and clarify how it can be used. The management also has to address critical patterns of behavior and so communication between the team members and the manager is an integral part of solving the problem as it facilitates maintaining control of the system. There is no punishment approach for groups that abuse Non-Standard since it is assumed they are not properly trained. However, meeting budgeted hours target does not grant rewards for individual performance either.
Organizational entropy suggests that unless positive pressure it applied onto the system, it will shift to pre-existing process conditions. Entropy is a force that enables change management programs to sustain improvements. The laws of entropy apply to lean manufacturing because without energy, commitment, and resources, the system can regress to a lower-energy state. Toys R Us will employ this principle in order to figure out how to reduce Non-Standard Time and hence, optimize productivity. The key is to keep the lean culture moving so submitting an idea that proposes change is not enough. One has to work to help implement the idea and establish controls that will enable maintenance of the improvements made while assuring the system will not regress to the previous state. Keeping employees reminded with updates regarding desired performance and budgeted hours targets allows them to stay on track with their schedules.