The last thing anyone should need is for me to explain or defend Bob Emiliani. He forgot more about lean just this morning than most of us will ever know. Yet here I go … to deal with the fallout from his recent post, Lean Heresy, in which he opened with the suggestion, “Let’s get rid of value stream maps.” In case anyone missed the point, he closed with, “So get rid of value stream maps and do kaizen instead.”
First, everyone needs to keep in mind that bloggers often engage in hyperbole.
Wikipedia: Hyperbole is the use of exaggeration as a rhetorical device or figure of speech. It may be used to evoke strong feelings or to create a strong impression, but is not meant to be taken literally.
Hyperboles are exaggerations to create emphasis or effect. As a literary device, hyperbole is often used in poetry, and is frequently encountered in casual speech. An example of hyperbole is: "The bag weighed a ton." Hyperbole makes the point that the bag was very heavy, though it probably does not weigh a ton.
With only a few words to make a point, we bloggers often use hyperbole as that literary device to quickly and effectively “create a strong impression”, but is not to be “taken literally”.
Bob is not really suggesting anyone abandon value stream mapping. What he is suggesting is that they be kept in the proper perspective. Value stream maps are a very good tool to frame up a problem. Everything done is done as part of a process. The problem is quite often not caused where it is found. It is caused by some upstream activity. Things that are done are quite often unnecessary if we tweak what we are doing upstream. Value stream maps help us to see that we can often save $2 somewhere by spending an extra $1 somewhere else. That is hard (often impossible) to see when we look at the business within its silos.
The solution to the problem – the chance to gain from an opportunity – does not come from the map, itself, however. It comes from data. Understanding the map is a very effective way to assure we are gathering and using the appropriate data. Looking only within silos we only gather and evaluate the data that impacts silo performance. Within the context of the map, we gather and act on data that impacts the overall business.
Once people thoroughly understand the concept of the process – they have the correct perspective and, therefore, the ability to gather and assess the right data – there is not much value in spending time creating a comprehensive value stream map. They can go straight to the data.
A while back I described a technique called the MATI Score developed by a pretty advanced lean company. It is a simple device that drives folks to look at the flow of a part from the receiving dock to its consumption in production and determine (M) the number of times it is Moved, (A) the number of Activities performed on the part such as inspection or counting, (T) the number of Transactions made in the computer systems, and (I) the days of inventory in hand. The MATI Score is nothing more than demonstrating Bob’s point. Moves, activities, transactions and inventory make up 99.99% of the waste you will encounter when assessing a part flow. They use the score to shortcut the value stream map and get right to the appropriate data needed to evaluate the problems and opportunities. Mapping the process to get the same data would be a waste of time and effort.
Bob wrote, “The real worth of current state value stream maps is to educate top company leaders, not to help workers make process improvements.” He is absolutely correct in saying that the value stream map’s greatest value is as a teaching tool, and that senior leaders are the ones usually in the greatest need of its educational value because they are the ones most steeped in traditional management. I mildly disagree with him concerning workers. Early on the value stream map can be helpful in their education, as well, although he is right in that production folks typically already know the source of their problems.
I see it this way: Value stream maps are like long division. It is very important that kids know how to do it and why it works before they are handed calculators. Once they understand it, however, kids would be foolish to do manual long division when there is a calculator available. In like manner, people embarking on a lean journey absolutely have to know what a value stream map is, what it shows and how to use one. Once that lesson has been learned – and learned deeply – it would be a waste of time to draw a bunch of boxes and lines and gather a lot of inapplicable data simply to comply with some misconceived notion that doing so is a prerequisite to being lean.