LEAN MANUFACTURING

Lean manufacturing focuses on the elimination of waste, formalizing a common source approach to machine design. Some general concepts to use when designing lean machines include,

- setups should be minimized or eliminated

- product changeovers should be minimized or eliminated

- make the tool fit the job, not the other way. If necessary, design a new tool

- design the machine be faster than the needed cycle time to allow flexibility and excess capacity - this does seem contradictory, but it allows better use of other resources. For example, if a worker takes a bathroom break, the production can continue with fewer workers.

- allow batches with a minimum capacity of one.

- people are part of the process and should integrate smoothly - the motions or workers are often described as dance like.

- eliminate wasted steps, all should go into making the part

- work should flow smoothly to avoid wasted motion

- do not waste motion by spacing out machines

- make-one, check-one

- design "decouplers" to allow operations to happen independently.

- eliminate material waste that does not go into the product

- pull work through the cell

- design the product so that it is easy to manufacture

- use methods that are obvious, so that anybody can understand - this makes workers portable and able to easily cover for others.

- use poke-yoke

- design tools to reduce the needs for guards.

To achieve these principles the complexity of a machine may be increased to decrease the manual labor and setup issues. In lean manufacturing the ideal batch size is one with no switchover time.