Page 44 - Design for Six Sigma a Roadmap for Product Development

22 Chapter Two

aspects of business operation by improving key processes. For exam-
ple, Six Sigma may help create well-designed, highly reliable, and con-
sistent customer billing systems; cost control systems; and project
management systems.
Lean operation principles are derived from the lean manufacturing
practices. Lean manufacturing is a very effective manufacturing strat-
egy first developed by Toyota. The key focus of lean manufacturing is
to identify and eliminate wasteful actions that do not add value to
customers in the manufacturing process. Because lean manufacturing
deals with production system from a pure process point of view, and
not a hardware point of view, it has been found that the principles of
lean manufacturing can be readily adopted in other types of processes,
such as office process and product development process. Therefore,
lean operation principles can be used to greatly improve the efficiency
and speed of all processes.
Compared with most of methodologies first introduced in the Six
Sigma movement—most of them are statistical in nature—lean opera-
tion principles can solve many operation efficiency problems effec-
tively that cannot be solved by statistical methods. On the other hand,
statistics-based Six Sigma methods can solve quality and performance
consistency problems effectively that cannot be addressed by lean
operation principles, so statistical methods and lean operation princi-
ples are really complementary to each other. Six Sigma organizational
infrastructures can also provide great help in leading project efforts,
training, and implementation. Integration of lean operation principles
and other Six Sigma methods becomes a dominant trend in the Six
Sigma movement from the early 2000s, and this integration is often
called lean Six Sigma (George 2003).

2.2 Process:The Basic Unit for the Six
Sigma Improvement Project

Six Sigma is a process-focused approach to business improvement.
The key feature is “improving one process at a time.” The process here
could be a production system, a customer billing system, or a product
itself.
What is a process? Caulkin (1995) defines it as being a “continuous
and regular action or succession of actions, taking place or carried on
in a definite manner, and leading to the accomplishment of some
result, a continuous operation or series of operations.” Keller et al.
(1999) define the process as “a combination of inputs, actions, and
outputs.” Anjard (1998) further defines it as being “a series of activities
that takes an input, adds value to it and produces an output for a
customer.” This view is summarized in Fig. 2.1.