I guess four months into this, it kind of makes sense to talk about waste. But rather than repeat what everyone else says, maybe I can contribute to the dialog and toss out some things to think about.
Identifying / Seeing Waste.
Taiichi Ohno had 7 wastes, a few publications say 7+1. I have always disliked trying to put “types of waste” into buckets. I have seen long discussions, some of them fairly heated, about which list of wastes is “correct” and whether this waste or that waste should be included, or whether it is included in another one. None of this passes the “So What?” test. (A related military acronym is DILLIGAS, but I’ll leave it as an exercise for the reader to work out what it means.)
The problem, as I see it, with lists of categories isn’t the categories themselves. It is that we teach people using the categories. We make people memorize the categories. We create clever mnemonics like TIMWOOD and CLOSEDMITT. We send them on waste safari with cameras to collect “examples” of various types of waste. Well.. you can’t take a photo of overproduction because it is a verb. You can only photograph the result – excess inventory. So which is it? People end up in theological discussions that serve no purpose.
Like I mentioned in an earlier post, teach it by inverting the problem. The thing people need to understand is this: Anything that is not adding value is waste. If you understand what value is, then waste is easy to see. It is anything else. What category of waste is that? Who cares. That only matters when you are working on a countermeasure.
What about “necessary waste?” Even Ohno concedes there is some of that. OK – ask “does this work directly enable a task that does add value?” Then it is probably necessary – for now.
Let’s take a real-world example from my little corner of the world – welding. Welding is pretty easy. If there is an arc, it is very likely value is being added. Not always, but it is a good place to start. Now – watch a welder. What does he do when he is not “burning wire?” (the phrase “and producing a quality weld” has to be tacked onto the end of this because I can burn wire, but it doesn’t mean I am welding.)
What stops the welder from welding? When, and why, does he have to put down the gun and do something else? For that matter, what makes him let go of the trigger and stop the arc? Is he loading parts into the jig? Does he have to jiggle those parts into place? Does he have to adjust the jig?
Special Types of Waste
In spite of what I said above, there are two types of waste that merit special attention. Most everyone who can spell “J-I-T” knows that overproduction is one of them. I won’t go into it here – anyone who is reading this probably already gets that at some level. If I am wrong about that, leave a comment and I’ll expand.
The other is the “waste of waiting.” Of all of the categories, overproduction is clearly the worst, but the waste of waiting is the best. Why?
It is the only type of waste that can be translated directly into productivity. It is the waste you are creating as you are using kaizen to remove the others. That is because all of your kaizen is focused on saving time and time savings, in the short term, turn busy people into idle people.
Let me cite some examples:
- The Team Member is overproducing. You put in a control mechanism to stop it. Now the team member must wait for the signal or work cycle to start again before resuming work.
- You remove excess conveyance by moving operations closer together. The person doing the conveyance now has less to do. He is idle part of the time where he was busy.
- Defects and rework – eliminate those and there is less to do. More idle people.
- Overprocessing – eliminate that, less to do.
- Materials – somebody has to bring those excess materials. Somebody has to count them, transport them, weigh them. Somebody has to dispose of the scrap.
- Inconsistent work or disruptions: Eliminate those and people are done early more often than they were. More idle time.
If you look at a load chart, these are all things which push the cycle times down. You have converted the other wastes to the waste of waiting.
Now your challenge is how to convert that wait time to productivity. What you do depends on your circumstance. You can drop the takt time and increase output with the same people. Or you can to a major re-balance and free up people – do the same with fewer, and divert those resources to something productive elsewhere.
Does something stop you from doing that? Do you have two half-high bars that you can’t combine onto one person? Start asking “Why?” and you have your next kaizen project. Maybe you have to move those processes closer together, or untie a worker from a machine.
- Don’t worry too much about teaching categories of waste. Teach people to see what is truly value-adding, and to realize everything else is waste – something to streamline or eliminate.
- In most cases your kaizen activity will result in more waste of waiting. This is good because wait-time is the only waste that converts directly to increased productivity.