Here you'll find a number of videos that demonstrate what is meant by the Lean concepts of SMED (Single Minute Exchange of Die), Kanban, Successive Inspection, Chaku Chaku, Moving Line and others. Not surprisingly, the companies employing these concepts are better than their competitors in Lead Time and Quality.
SMED
Single minute exchange of die. This is the name given to a series of techniques developed by Dr. Shigeo Shingo (co-developer of Toyota Production System with Taiichi Ohno) that analyzes and seeks to reduce all the aspects of operator involvement in the setup and changeover of machines.
The simple steps of the SMED system are:
- Observe and document ALL setup and changeover activities,
- Separate the external steps from the internal steps,
- Convert internal steps to external steps,
- Streamline ALL external and internal steps.
Most production managers are quick to see the benefits of increased up-time and productivity from machines that have experienced the results of good setup reduction routines, however, the greatest benefit to quick changeover is the manufacturing flexibility and enhanced response time that allows the production of smaller lot, larger variety runs on the same machine.
This is another example of translation difficulties from Japanese into English. The intent of SMED was stated by Dr. Shingo as changeover within ten minutes, or single digit.
Flow
One of the elements of Just in Time production, flow production is defined as moving the product and/or information from one value-added step to the next continuously. Also often referred to a one-piece or single piece flow.
Cellular Design
Cells are formed by grouping equipment in a process sequence by following the three principles of Just In Time processing; flow according to takt time, inventory pull through signals generated by demand, and use of minimum resources to make or repair only what is needed – when it is needed.
Equipment is positioned within a cell so that production goes from one adjacent machine to the next, for most products processed within that cell. Right-sized equipment is preferred, not only to enable single-piece flow but also to physically fit within the cell so as to minimize operator motion.
A U shape is preferred because it minimizes walking distance and allows different combinations of operations for a family of products. The cell should be designed as small as physically possible yet with enough room for the necessary number of operators to meet maximum demand. There should be no room in the cell for inventory other than Standard WIP.
Progress tracking is made simple by cells; one can stand at the opening to a cell and see the amount of product already completed and that awaiting processing. The goal is to not have product leave the cell for any reason, to further that managerial ease.
Poke Yoke (error-proofing)
Mistake-proofing and fool-proof devices (poke-yoke) made by designing parts, processes, or procedures in a way that mistakes cannot physically or procedurally be possible. Mistake-proofing commonly refers to the use of fail-safe devices in machine operations that detect or prevent defects and insure quality. This is the key ingredient that is added to automation to yield autonomation.
In a lean culture errors are a learning experience; the cause is learned and eliminated. People are not blamed for errors in a lean culture – processes are. In a lean culture people are known to become careless, due to fatigue, lack of attention and any number of other causes. A good lean culture recognizes they need to have simple cost-effective systems to prevent such lapses from affecting quality, and designs them into every process.
Just In Time (JIT)
Production methodology reliant on heijunka and characterized by single piece flow production accomplished according to takt time and pull production to use the absolute minimum resources to make only what is needed – when it is needed.
JIT is a result of single piece flow, adherence to takt time, and pull rather than a lean concept itself. It is not something you can start tomorrow, yet it is a pillar of the Toyota Production System. Because of the misunderstanding of the complexity of JIT people tend to blame JIT for any shortage experienced early in a lean "journey," even when the three elements necessary for JIT are still being built. For this reason, early in any lean transformation all employees should be made to understand JIT and be assured that processes that have it will be made known.
Miscellaneous
Each of these videos contain several Lean concepts.
An interview with Dr. W. Edwards Deming is included here, in three parts.