Cheatin' With MATI

by BILL WADDELL

I thought I'd give you a break from all of the grand philosophical ranting and actually write about something practical.  Not to worry. I won't make a habit of it - after all, I have a hard earned reputation to protect.  From time to time, however, it is important to demonstrate to myself that I do actually know a thing or two about lean shop floor stuff. 

First, a couple of disclaimers:

Greg Wahl - CEO of Wahl Clipper - actually came up with this idea while I was working for him.  I tweaked it a bit and implemented the concept, but he is really the brains behind the MATI Score idea.  That said, he still has a full time day job, while I am back to consulting, so I'll write it up and shamelessly take more credit than I deserve. 

Second, this is for the experienced lean folks.  If you are new to value stream mapping, or haven't done much with charting your processes, you really should skip this one.  Using the MATI Score tool without having a solid foundation in mapping manufacturing processes is going to lead to trouble down the road.  It is kind of like giving calculators to elementary school kids before they have learned to do math manually.  They will get the right answers, but they won't really know why.  Sooner or later that will catch up with you.

MATI stands for (M) Moves; (A) Activities; (T) Transactions; and  (I) Inventory.  It is a method of identifying and categorizing all of the non-value added waste in a manufacturing process without going to the time and effort of doing the detailed flow charting that goes into process mapping.  In other words, it is a calculator or a short cut.

In the course of a kaizen event, or any other effort that is intended to improve or modify a process, you simply add up those four things:

Moves - the number of time a part is physically moved in the process

Activities - the number of times a person has to do some non-value adding work to the part (the most common ones are performing a quality inspection or a cycle count)

Transactions - the number of times the part has to be transacted in your accounting/ERP/inventory control system

Inventory - the number of days of inventory on hand (if you need to calculate this in terms of weeks or months of inventory in order to keep the number manageable, you are probably not ready for the MATI Score tool.)

The MATI Score = M (moves) + A (activities) + T (transactions) + I (inventory)

Obviously, the lower the MATI Score is, the less waste there is in the process.

The purpose of the MATI Score is to quickly determine the amount of waste in the process in the current state, and to just as quickly evaluate the waste reduction impact of the changes you make in the future state.  It is intended to make sure that you are not simply pushing the inventory or other waste to another part of the process, without having to flow chart everything.  The goal, of course, is to continually reduce the MATI Score of every process. At Wahl it is required that a before and after MATI Score be calculated as part of every kaizen event.

It also provides the benefit of quantifying waste.  It forms the basis for measuring overall improvement, and gives you a quantified method for identifying the processes most in need of attention.

The genesis of the MATI Score idea was the need for some reassurance while we were transitioning considerable amounts of inventory from a warehouse to point of use storage, from MRP push to Kanban, and from a functional production layout to value streams.  With so many changes taking place simultaneously it was very helpful to have a quick tool to assure that we were not simply rearranging the waste, and that the changes were resulting in real improvements.

So there you have it.  The MATI Score does not eliminate the need for process mapping and I do not want anyone to leap right to it.  But if your mapping skills and knowledge are solid, it provides a quick and effective tool for tracking and  driving the non-value adding elements out of your manufacturing processes.

(How many other CEOs understand and live lean well enough to come up with an idea like this?  That the CEO came up with this might help you understand why Wahl is selling Made in the USA consumer products to Walmart and taking market share from their Made in China competitors.)

Comments

[Jon Miller]

I like this. The Inventory measure is the only one that seems to be on a different scale. Rather than days of supply, perhaps stock points (before the process, within process, at end of process) as a measure of continuous flow? Days of supply is a good measure, but it could be <1 and you could still have lots of WIP, many stock points, a.k.a. way too much.

[Bill Waddell]

Thanks, Jon. I tend to agree with your suggestion. The best way to calculate the inventory component probably depends on the company and the situation, however. Whether to break the inventory into its various elements, assign it some sort of weight, or leave it alone is a decision that management will have to make that will determine the priority of reducing inventory versus eliminating the other wastes.

My personal inclination is to put relatively little emphasis on inventory. If the cmopany reduces the number of moves, transactions and non-value adding activities, the inventory will usually take care of itself.

[Matt Holst]

Identifying and quantifying wastes is obviously the greatest benefit for the MATI scorecard, but I noticed that during the course of an RIE, it really helped illustrate the idea to the operators (and everyone) who are not usually exposed to the everyday Lean focus, probably because of it's simplicity. It SHOWED them what we were trying to do, instead of some Industrial Engineer or some other Team Leader TELLING them what we want to do.

[Bill Waddell]

Thank you Matt.

For those who don't know him, Matt is an IE and a lean leader at Wahl, and was the first and best user of the MATI Scorecard.

[Rob Wagner]

Hope you understand the hidden traps in using this metric without its natural, and necessary, countermetric. I'm hoping that you'll grasp when MATI also becomes counter-productive (as they all tend to become) just like the other metrics we commonly scorn.
It becomes all too easy to rely on a metric to run a business. It is quite another thing to understand what is really behind those numbers and what is truly of value to the business.