It was really informative Jon. It may be confused though, I take it that this is the follow through on a stuck A3 Strategy Sheet? Is this a detailed approach on alternative steps to address the current "botched" situation?

The PDCA cycle has always been incorporated in the A3 Strategy Sheets as part of the complete cycle of any project after defining the project's aim/s, responsible ownerships and setting the corresponding time tables for completion.Do you still need this if the A3 Strategy Sheet is covering the whole cycle of the project and is proceeding as planned and approved by the stakeholders?

Hi John,

Most of lean world does not use the A3 sheet yet, but value stream mapping by itself is very popular. So to answer your question directly, "no".

Value stream mapping is often a team activity preceding or as part of a kaizen, taking 1-5 days or more on a big sheet of paper, collecting data and "grasping the situation". It can certainly be a tool that is used as part of the A3 process. Actions that result from VSM should follow PDCA.

But most users of VSM do not incorporate it into the A3 process, as yet.

I see VSM and A3 as different systems entirely. VSM should be, I believe, the first step in understanding how things really are in your plant (or other business entity), how it will look in your "ideal" state, and where you should use specific tools to improve the flow. A "map" shows where the flow stops and that is where our energy should be put. The map allows us to really see what is going on as a whole and how each part relates to the others. It is a vital process, but comes before any A3 strategy or kaizen plan. The current prevalence of conducting a mapping exercise just prior to a kaizen event defeats the entire purpose of the map. The map should be THE MAP--directing our lean journey.

Ok, but what do you do when one machine is shared by several product families ?
It looks fine, because the takt time is for instance 15 min/piece, and the machine cycle time is 5 min/piece. But in fact the machine is not available 100% for this product family...

If a machine is shared by more than one product family, and a product family is defined as a value stream (as opposed to a value stream that contains several product families for whatever reason) then this will most likely be shown with a supermarket or inventory stock point after the process. This inventory represents the build-up of stock of one product family, to maintain supply during the time when the other type is being produced.

There would also be a changeover time indicated in the data box, the number of shifts the machine is operated and even the percentage of available capacity can be shown.

Once it is clearly established that a machine is shared between multiple products, the takt time for that machine is calculated separately based on the net available time divided by the total customer demand for all product families. So long as the average weighted cycle time is lower than the takt time for all product families, there should be no problems. But in fact it is best to fill out what is called a Table of Production Capacity by Process (or Process Capacity Table) to figure out if you have enough capacity.

Changeover times will need to be deducted from available times, based on the frequency of changeovers per shift. In fact Overall Equipment Effectiveness (OEE) should be taken into account if it is measured for that machine when calculating takt time.

Note that even if machines in a value stream serve only one product family, the available time (number of shifts operated) may be different, so it is important to ask these questions and do the takt time calculation per each process.