Page 198 - Lean six sigma demystified

Chapter 5 Redu C ing d efe C t S with Six Sigm a 177

Defining Countermeasures

Action should culminate in wisdom.
—The Bhagavad Gita

Purpose: Identify the countermeasures required to reduce or eliminate the root
causes
Like good weed prevention, a countermeasure prevents problems from
ever taking root in a process. A good countermeasure not only eliminates
the root cause but also prevents other weeds from growing.

Verifying Results

Purpose: Verify that the problem and its root causes have been reduced
To ensure that the improvements take hold, we continue to monitor the
measurements (CTQs). Both the control chart and Pareto chart will improve
if the countermeasures have been successful.

1. Verify that the indicators (CTQs) used in step 1, Focus, have decreased to
the target or below.

2. Verify that the major contributor identified in the Pareto chart in step 1
has been reduced by comparing before and after Pareto charts.

To ensure that the improvements take root, we need to develop a flowchart
of the improved process and a way to measure its ability to meet customer
needs.

There is always a best way of doing everything.
—Emerson

Sustain the Improvement (Control)

Purpose: Prevent the problem and its root causes from coming back
Like crops in a garden, most improvements will require a careful plan to
ensure they take root and flourish in other gardens. To transplant these new
improvements into other gardens will require a control plan. Sustaining the
improvement requires control charts and sometimes histograms to monitor
and maintain the new level of improvement.