Eliminate all Muda

Manufacturing Engineering, Apr 2001 by Mika, Geoffrey

In the original Toyota production system, anything that adds cost without adding value to a process is Muda (waste). The Toyota system identifies seven kinds of Muda:

* Overproducing,

* Wasting time,

* Transporting,

* Over-processing,

* Inventory (WIP),

* Excess motion of operators and workers,

* Scrap and rework.

The seven wastes are now ten. The seven identified years ago at Toyota remain important today. But when you look at how the manufacturing plan comes together, it's clear there are three additional types of Muda in areas we haven't addressed.

* Human underutilization,

* Improper use of computers,

* Working to the wrong metrics.

People who know the most about a job ought to make the most decisions. If they don't, we're underutilizing people. Human underutilization occurs when, instead of teaching people how to make decisions affecting their jobs, organizations give them jobs a robot could do.

Two very effective ways to capitalize on the abilities of workers are suggestion systems and kaizen programs. Companies that believe people have more to offer than loading and unloading machines benefit when employees are encouraged to offer ideas. Improved productivity and product quality are consequences of such involvement by shop-floor workers.

Improper use of computers is one of the most important forms of Muda. The problem with our reliance on computers is that the powerful databases and Enterprise Resource Planning (ERP) systems that were supposed to integrate and control the disparate parts of organizations have added complexity, cost, and waste instead of decreasing them. Companies spend money on hardware and software to help run the business, only to discover they must either change the way the business is run or add modules to what was believed to be a complete software system.

A company's initial applications for computer technology should be in engineering and manufacturing. Some engineering departments design products that are almost identical to products they've engineered in the past. In one case, a company had over 11,000 SKUs for turbochargers. They didn't know how many were duplicates. Time spent redesigning a product that has already been designed is a major example of the improper use of computers.

An effective use of computer power would have permitted the company to perform sorts on the key attributes of all their turbochargers. The company probably would have discovered that it had a family of about 10 different turbochargers, and all the others were variations on those designs.

Another effective use of computer power is to link engineering data with data from process sheets, and from the total productive maintenance (TPM) effort. The objective is to make data available from one source, instead of leaving it scattered over servers in several departments. Such work must be done in a format that workers can access, understand, manipulate, and use. Many companies have programmers who work in a language that only a few employees can manipulate, and are indifferent to manufacturing.

Most Manufacturing Resource Planning (MRP) systems illustrate the improper use of computers MRP is built on a push system of production. It is the complete reverse of a lean, just-in-time production system. When scheduling work on the shop floor, avoid MRP. if possible. in favor of a pull system with manual kanban cards.

Make the computer a tool for people on the shop floor. Concentrate on computerizing engineering drawings, process sheets, standard work combination sheets, and maintenance and TPM data.

To avoid working to the wrong metrics, avoid such measures as amortization schedules, work standards, and earned-hour credits. They lead to distinctly un-lean thinking.

Such metrics have nothing to do with making good parts or creating a good process. They yield accounting numbers that many companies cling to for all the wrong reasons. Also avoid keeping a running total of output for use at the end of the month. It doesn't help you achieve the lean goal of being able to make every part every day.

Just six metrics should be at the core of your lean measurement system: first-time-through capability; dock-to-dock time; overall equipment effectiveness; build to schedule; value-- adding ratio; and units per labor hour, costed.