By Jon Miller | Post Date: July 26, 2007 11:48 PM | Comments: 1
Sorting through old documents as part of my regular 5S at the office I came across another consulting firm's Lean training materials, collected about a decade ago. These explained Lean manufacturing and the idea of eliminating waste using the acronym CLOSED MITT. I am told this comes from Boeing, or at least that it was popularized there.
CLOSED MITT stands for the 10 types of waste (yes, ten) commonly found in all processes. They are:
It's ironic that after adding to the original list of 7 wastes, the author of CLOSED MITT did not reflect on "complexity" being at the head of this enlarged list. If we use Occam's Razor, a principle that states that the simpler theory is best (named after the 14th-century English logician and Franciscan friar William of Ockham) a shorter list seems to be in order.
We need to keep an open mind in finding and getting rid of waste. Certainly no waste should be allowed to persist a moment longer than necessary, even if we do no agree on what to call it. I have always found the 7 types waste to be sufficiently descriptive for the wastes around me.
For example "energy" waste from the list above can be included in the waste of processing, since more resources than necessary are being used to perform the process, and resources take energy in some form. You may have a near-perfect process, but if the building is using too much air conditioning or if lights are left on where not needed, in a macro sense there is still processing waste (energy waste).
The "space" waste above should rightly be considered inventory waste since space is an asset you are paying for if it is owned, or if the space is leased it should be considered as a form of processing waste since it is a variable expense that is unused but paid for, heated, lighted, cleaned, etc. but adding no value.
Although not typically included in a list of wastes, we should consider environmental contamination to be an example of making defects. The defect created is not a product but the natural environment around the process. At some point this environmental damage (defect) will need to be corrected or the environment (product) will become unusable (scrap).
Another type of defect is health and safety losses in the workplace. Safety is often in a separate category from the 7 types of waste, or "the 6th S" add-on to the 5S, but "safety first" should be taken seriously by any serious Lean effort and must be a prerequisite and foundation of a Lean system. A safety incident is an example of a defective process that needs correction.
Simpler theories, shorter lists, and smaller formulas are better because they are easier to test, remember and apply.Comments are moderated to filter spam and inappropriate content. There may be a delay before your comment is published.