Most Lean
Manufacturing elements either reduce variability, adapt to it or both. This can
be a useful perspective for developing Lean Manufacturing strategy. Here are some examples:
TQM/Six Sigma
Capability analysis, part of SPC, ensures that the inherent variability in a process is small
enough to ensure defect-free production. Control charts discover unrecognized sources of
variability before they can produce defects.
Grouping similar parts (Group Technology)
and processing them in workcells reduces the variability from differences in routing. It also
reduces the variability associated with transport and batching.
Kanban reduces variability from the scheduling system. It smoothes the flow and helps reduce
batch sizes.
|
Teams reduce variability in many ways: their lines of communication are shorter and more
predictable; their responses to situations more consistent; they enhance the effects of
workcells, SMED and other Lean elements. Teams both reduce variability and enhance the ability
to cope with it.
Shigeo Shingo's SMED approach reduces setup
cost and enables lot size reduction. This, in
turn, reduces the variability from batching. In addition, SMED makes setups not only shorter, it
makes them more consistent in terms of time and quality.
Mixed Model Production
Running multiple products on a production line smoothes upstream demand and, hence, reduces
upstream variability. Configuring a production line is an example of coping with unavoidable
customer demand.
|