Setup Reduction
Setup Time is defined as the time to change from the last item of the previous order to the first good item of the next order.
Setup includes preparation, replacement, location and adjustment activities (see below). When analyzing setup activities, note whether the activity is internal or external. Internal setup activities require an inactive (shut down) process, meaning that no orders can be run while the setup activity is taking place. External setup activities may be done while the process is operational. They are offline activities.
Incredible reductions is total setup time have been realized simply by making internal activities external activities. The following four-step approach may be used to reduce setup times (ref: Lean Six Sigma, by M. George, 2002, McGraw Hill):
1. Classify each setup step as either Internal or External. Internal steps are those done while the process is inactive. External steps are done while the process is operating.
2. Convert Internal steps to External steps. We want to reduce the time the process is non-operational, so we need to reduce the time associated with the Internal steps. The quickest way to do this is to do as many of these steps as we can while the process is operational. For example, if we can collect the money from the customer as their burgers are being cooked, then the total cycle time is reduced.
3. Reduce time for remaining Internal steps. There are some Internal steps that cannot be done while the process is operational. We now want to concentrate on reducing the time required to complete those steps that require the process to be delayed. For example, since the burgers cannot be cooked until we know what the customer wants to order, we will try to reduce the time it takes to place the customer order.
4. Eliminate adjustments. Adjustments, as discussed in the Analyze stage, can be reduced through effective process control. Designed Experiments may be used to understand the causes of process variation that precede the adjustment.
A Pareto Diagram can be useful to prioritize the setup time categories. In the example shown, Location dominates the setup, so is a natural target for improvement.
Preparation: Preparation refers to the tasks associated with getting or storing tools or WIP needed for the process. For example, retrieving printer paper from closet; downloading the process instructions on the computer; moving completed items to the next process step; starting-up software that we need to process the order, and so on.
Some suitable actions to reduce the time associated with Preparation include:
Convert from departments to work cells to minimize the time required to move the finished product to the next process step.
Store tools and materials locally, such as advocated by the 5S principles.
Convert to Always ready to go. Make the software or instructions instantly accessible
Replacement: Replacement refers to the tasks associated with adding or removing items or tools. For example, the movement of test fixtures; loading of new material into the hopper; loading paper in the copy machine.
Actions to reduce Replacement times include:
Simplify setups. Reduce the number of steps required, such as through a redesign of fixtures.
Commonality of setups for product families. When we establish the same setup procedures for multiple items, we naturally have less instances of change required, reducing the setup time. This is the 5S tool of standardization. The process is simplified by reducing the number of “special items” that are processed: the higher the process complexity, the longer the cycle time. Henry Ford, in offering the first affordable automobile, realized the efficiency advantages offered by standardization. His motto “any color you want, so long as it is black” exemplified the notion of standardization. The modern approach to standardization is not that we need to limit options, but rather that we need to recognize the advantages of simplified processes, and seek to remove “special cases” where they provide little value at the cost of increased cycle times. Decision points and subsequent parallel paths on flowcharts provide indication of process complexities that can sometimes be avoided. By grouping parts or services into families, we can recognize that there are common methods that can be applied, thus simplifying processes and reducing overall cycle times.
The 5S tools of sorting and straightening also help to reduce movement and wait times.
Location: Location tasks are those associated with positioning or placement during setup. Examples include setting temperature profiles for heating; Adjusting cutoff length for specific product; Placing the chunk of deli meat in the slicer.
Actions to reduce the time associated with location include:
Poka yoke (mistake proofing the process).
Commonality of setups as previously mentioned (The 5S tool of standardization)
Adjustment: Adjustment refers to tasks associated with ensuring correct process settings. Examples include Monitoring temperature of furnace; Checking cutoff length; proofing copy before printing.
A suitable action to reduce adjustment time is process control. If we can improve the repeatability of the process, then the adjustments would not be necessary. Often this is achieved though robust design methods.