Muda Walk for a Month – Week 1: 09/01 to 09/09

Muda Walk for a Month – Week 1: 09/01 to 09/09
(This is a bonus week and includes a holiday in the USA)

The Theme this week is to attack Over Production and Inventory

We are starting the Muda Walk for a month by looking for the waste Mr. Imai says is the mother of all wastes: OVER PRODUCTION. Over production usually leads to many other wastes especially inventory.  Over production in construction is not the same as making too many parts like they do in manufacturing.  Hopefully, we don’t fabricate more parts than are ordered.  In construction we over produce when we order material or fabricate too much or too soon. For example, when the shop fabricates duct ahead of schedule just to keep the shop busy, there is excess material at the end of the day somewhere. It is either taking up room in the shop, out in the yard or it may be shipped to the job site. There it is unloaded by workers who really should be doing install – aka value added work.  Storing fabricated material at a job site runs the risk of the General Contractor asking us to move it. We have to move it several times before it is finally installed. (Moving material is another waste.) Stockpiling material or parts either in a warehouse or at the job site is inventory caused by over production.

INVENTORY itself is waste. It costs money – more than you think! Some inventory may be called strategic inventory – inventory that is necessary to keep the crews installing. Any additional inventory is excess and waste. The challenge is to “see” the difference.  Any material or parts not currently being used by the customer is waste. This includes raw material, work in process and final fabrications. This type of waste includes extra parts, excess space and unused tools. Look for stashes and workers’ own stockpiles - they are inventory (waste) too.

Inventory is a double serious waste because it produces or hides other wastes. Companies and job sites often accumulate inventory because of unreliable support from their shop, vendors or the material delivery function or because of efforts to save money through a bulk buy. Usually the money saved in bulk buys is spent by the hidden, but real, costs of holding inventory.  Companies also accumulate inventory because of weak planning and poor job site coordination.

Go look for over production and inventory. Over production is often spotted by stacks of material, parts or tools. That may be in a warehouse, a trailer, in the yard or at the job site. Stacks, piles or loads of material is caused by over production and are non-value added from the customer’s viewpoint.  Ask “Why” do we have these stacks?  Ask why enough times to get to the root cause.

Implement improvements. Try something; if it doesn’t work try something else.

Record your improvements.

Remember: Go and See – Ask Why – Show Respect – Do No Harm

Just DO IT