Page 279 - Lean six sigma demystified

Chapter 8 SuStaining impr ovement 257

LSL USL

Target
Figure 8-6 • Minimal loss from variation.

Stabilize Your Process

When the process moves around like this example, it probably means that
someone is changing the settings, without any real need to. Deming called this
tampering. Let the process run and then adjust the settings to move it onto the
target. Then leave it alone unless it starts to drift.
? still struggling

When you create a control chart with the QI Macros, if there are no “red” points
or lines on the chart, then the process is in statistical process control.

Reduce Variation

Once the process is stable, use process improvement to reduce the variation
(adjust the process to reduce the variation from the target).

Reduce Loss

Stabilizing your process and reducing the variation will, in turn, reduce the cost
of the Taguchi loss function. This will save you and your customers’ time and
money (rework, waste, and delay). And customers are smart. They can tell the
difference between two different transmissions, and they can tell the difference
in quality between you and your competitors.