Over the years, I have worked with many companies trying to find ways to reduce the time their machines sit idle while changing over from one job to another. When a machine is being set up, it is not making parts.
Over the years, I have worked with many companies trying to find ways to reduce the time their machines sit idle while changing over from one job to another. When a machine is being set up, it is not making parts. Over the course of a year, minutes lost to setup time can result in many hours of lost production.
The theory behind reducing setup times has not changed significantly since Shigeo Shingo introduced his groundbreaking Single Minute Exchange of Dies (SMED) concepts more than twenty years ago. By applying these concepts, thousands of manufacturers have cut their setup times from 50 to 75 percent or more. In addition, machine tool builders and tooling manufacturers have introduced new technologies such as pallet changers, increased toolchanger storage capacity, chip conveyors, simplified CNC programming, quick-change tooling, and simplified tool presetting, all with the express purpose of reducing machine setup times.
The easiest—and most effective—way to reduce machine setup time is to prepare in advance the three things that are required before any piece of equipment can be set up and operated: information, material and tooling. Although you may be able to start a setup without all three, you cannot complete a setup if you are missing any of them. How many times have we seen a machine sit idle waiting for just one of these things to show up? An effective setup procedure practically guarantees that everything needed to complete the job is there ahead of time. Let’s take a closer look at each of these critical components.
Information. As obvious as the need for complete and accurate information is, this component often gets overlooked, especially when a machine is being set up to run a repeat job. Information necessary to a setup can vary, but it usually includes a part print or specification describing the part’s characteristics; a setup record to indicate required tools, fixtures and machine settings; a program for any CNC machine that is computer numerically controlled; and a work order indicating the quantity of parts and any customer-specific instructions. All of this information needs to be read and understood before the actual setup begins. Therefore, it is essential that the setup information be delivered to the machine and placed in a highly visible location before the previous job is completed.
Material. Without material, no parts can be made. Once the setup person is given the information about the next job, he can check material requirements and either obtain the material (if the material is stored nearby) or take action to have it brought to the machine. Ideally, there should be a clearly marked staging area at every machine to hold material required for the next job.
Tooling. Tooling can cover a range of items. Cutting tools required by the machine need to be readily accessible. If machine tool storage capacity allows, the ideal place to keep tools is in the machine itself. Hand tools needed for measuring or secondary operations performed at the machine also need to be available ahead of time. This is much easier to accomplish if they are routinely stored at the point of use. However, company policies may necessitate that products, such as inspection gages, be obtained from a controlled area. Likewise, any special fixtures required for the next job must also be brought to the machine and checked ahead of time. Maintaining such fixtures on, or close to the machine will make this task easier.
Look at some of your pending machine setups and answer the following questions with “always,” “usually,” “sometimes” or “never.”
An answer of “always” to all three questions assures shorter setup times and an increased likelihood that your machines will be cutting chips sooner. Any of the other three answers indicates there is an opportunity for your organization to do a better job of managing your machine setups.blog comments powered by Disqus