tighter approval controls for engineering change

6 Sigma Case Study – CAT : Part 2 DCM/10.08/AS-RR/TS
Cranfield School of Management 1
6 Sigma Case Study – CAT : Part 2

This case was
prepared by Alan
Smart, Cranfield
School of
MK43 0AL,
Richard Renshaw
© Cranfield
School of
Richard Renshaw
October 2008.
All rights
Improve Phase
To summarise from part 1 of the case, the process has
several deficiencies:
Significant rework is generated at several points
on the assembly line
Work stations have been set up to accommodate
rework rather than eliminate it
There are at least 19 people working on non value
added rework type activities
Rework is generated because many assemblies
and components do not correspond with latest
The rework and rework loops inflate the number of
finished and partially finished goods stock (qty?)
On average 11 drawing changes are made every
day, so components in the supply chain become
The dealer and marketing requests are around
90% of all changes implemented and therefore
drive a high proportion of the rework
The current engineering change workload is higher
than the engineering change capacity available
The engineering change workload is greater than
the organisation’s ability to communicate and
implement effectively.

6 Sigma Case Study – CAT : Part 2 DCM/10.08/AS-RR/TS
Cranfield School of Management 2
The following are improvement suggestions.
Apply tighter approval controls for engineering change
requests that emanate from marketing and dealers. Use a
standard cost model which makes cost or sales justification
clear, to enable comparison and prioritisation
Use some of the savings from eliminating 13 operational
rework roles to hire 2 more engineers.
Batch lower priority engineering change releases into monthly
buckets to enable better control and communication to both
the assembly line and suppliers; most engineering release will
be on the same day in the month (excludes safety critical and
market failures)
Conduct an audit with all users of drawings to eliminate
documents of the wrong revision level and replace them
Investigate what would be required to implement an improved
document control system
Discuss the merits of these improvements, decide on priority and
consider the timescale for implementation.
What additional, short-term actions may be necessary to improve
the company’s situation?