If you travel into any machine shop, office or hospital facility in the world guaranteed you have seen a changeover before. The changeover occurs in between the last good part or service until the next good part or service. Some examples would be changing tooling, patients service completion, changing paper in a printer or taking one batch of cookies out of the oven in order to start a new batch. This "in-between" time is usually spent performing wasteful activities which often result in long changeovers that inevitably eat up value added time.
In about the late 1960's a brilliant industrial engineer by the name of Shigeo Shingo was given a challenge to increase the capacity of his shop floor without the use of excessive capital expenditures. In other words he could buy no machines. After watching the machines on the production floor, Dr. Shingo noticed a machine sitting idle. It was then that Dr. Shingo realized that by focusing on this "changeover" or "setup" time, production on the floor could be increased. He then set an objective saying that no changeover should take more than 10 minutes, in fact they should all be under 10 minutes. This is where the reference to "single" in single minute exchange of die comes from.
Setup and changeover time can eat away time for value added activities such as transforming materials or treating patients. By focusing on reducing this changeover time companies can often reduce or improve setups or changeovers by more than 60%.
How It is Performed?
Although we will not outline the details of Dr. Shingo's system described in the book, most systems are generally the same. However we do recommend getting a copy of the master's book and reading it. Here we will share with you some insight relating to our ©REDUCE methodology which is simply a mnemonic used to help others remember some key steps in the system.
1. Required data - Once you have identified the area that you changeover or setup reduction will take place in you will need to make sure that you collect the required data for the project. Some suggestions for data you might want to collect are yield, cycle times and of course any types of variation in the changeover.
2. Engage with VSM - Now that all the data is collected and the team is focused on objectives it's time to lay out how the changeover actually occurs in the current state. The most effective way I have found in seeing the entire process is by mapping it out. One very valuable thing that you can do even before you start your value stream is to videotape the process. Videotaping can allow you to slow down or speed up the process in order to see everything happening. What we hope to gather here is a complete understanding and visually laid out map of the sequence of the process in its current state. One thing to note is that if inspiration hits for improvements place them in a parking lot but do not act yet, we want to refrain from jumping to solutions until the time is right and all elements of the changeover have been taken into consideration.
3. Differentiate Internal and External steps - With a clear understanding of the process and the ability to review our video if need be, we are ready to separate Internal ( can only be performed when the machine or process is not active) from external (can be done when machine or process is active).
4. Undergo Conversion - Now we are ready to convert internal and external setup steps. The objective here is to change as many internal elements as possible to external steps. Some common improvements for conversion are preparing parts, tools or information in advance of the changeover. You may also want to look for opportunities to use clamps in place of screws and bolts or minimizing the need for test runs and any adjustments associated with the activity.
5. Clean up the process - After conversion of internal and external steps has been completed we want to clean up the overall value stream removing any types of waste remaining in the process. Some of the more common ways to clean up the process are by reducing the need for transportation, motion and waiting or running operations in parallel of one another. As a last resort teams sometimes look to mechanize, automate or invest in robotic activities. Often these type of improvements require significant capital expenditures, which is why we want to be sure we do everything we can possibly do before looking to investments that may yield only a small cost to benefit outcome.
6. Ensure the steps are work - As a final activity it is important to ensure that the steps work and are in balance. We don't want to place any unnecessary strain on workers or create a process that only works for a bit of time only to result in poor yield or excessive variation in the process.
Focusing on changeover and setup reduction can dramatically improve production time in an organization. Additionally it often results in lower operating costs, reduction of lot sizes, Improved response to demand placed on the organization and less inventory on all levels.