We have described half of the waste categories in my COMET TAILS model. (I will work on an alternative model, though I should point out that Boeing’s model uses the acronym CLOSED MITT, so I’m not so sure mine is that bad.) Now we will look at the second half, the TAILS.
Moving material, equipment, tools, people, etc. from location to location in a facility never adds value. It is always a waste (of time, energy, labor). The greater distance something is moved, the greater the waste. Minimizing transport is a function of workplace organization, which the trainer should also be looking to improve (not merely write about the current state of organization).
A: Available Space
As space in a facility fills with “stuff” (over-produced goods, scrapped materials, old equipment, files, etc.) the space available for productive work is reduced. Maintaining control over space can make the difference between having a location to expand or having to find a new location.
I: Idle Material
When materials stop in mid-process, they tie up not only space but capital. From an accounting point of view, each process (value-adding) step adds value, and increases the inventory value (not a good thing). Idle material is a subset of over-production (described in Part 4). No material should be committed to the process unless we know that it will move through the process stations to completion, and to a customer.
Labor is a function of time and worker. In the vast majority of cases, when we hire an employee to produce goods, we are paying for that person’s time. They spend an hour “on the clock,” they get paid a certain amount (their wage) regardless of what they did or did not accomplish during that hour. To the extent that their time was not used on product manufacture, a waste has occurred. Waste reduction depends on maximizing the time spent adding value.
Any time material into the process does not come out as intended, scrap results. When scrap occurs, material is lost, time and labor are wasted (time, material and labor must be applied again to achieve the intended production). The scrap material must be handled specially (ISO-9001 mandates a procedure for segregation of non-conforming product). The only thing worse than producing scrap is having it find its way to a customer.
Those are the categories of waste. Three things to consider regarding waste:
1. While the discussion focuses on production, these wastes apply similarly to other areas, including “office” functions. Every function has (or should have) an identifiable intended outcome including time for completion. Any of the issues above can impede completion of any function.
2. There is another waste category, that often (rightfully so) finds its way into waste models. That is Safety. Failures to maintain safe working conditions can quickly cause a number of wastes to occur as a result of an injury. Most manufacturing organizations consider safety to be a prime consideration, if not “the most important thing we do.” Failures in safety often result from the same types of behaviors and lack of control that creates waste. Safety issues will suggest the potential for other waste issues, and vice versa.
3. When a waste occurs, it never occurs in isolation. This was hinted at in the discussion of Scrap above. For example, a waste of material means lost time, wasted labor, consumed energy, depletion of available space, etc. If too much of a product was made (over-production), material, time, labor, energy are all consumed, as is space when the over-produced material is stored–of course it has to be transported to the space as well.