SIX SIGMA FUNDAMENTALS - Software Design for Six-Sigma: A Roadmap for Excellence - page 152

service offerings focusing on the reduction of defects. DFSS (Design for Six Sigma),
however, is used in the design of new products with a view to improving overall
initial quality.
Six Sigma evolved from the early total quality management (TQM) efforts as
discussed in El-Haik and Roy (2005). Motorola initiated the movement and then
it spread to Asea Brown Boveri, Texas Instruments Missile Division, and Allied
Signal. It was at this juncture that Jack Welch became aware from Larry Bossidy
of the power of Six Sigma and in the nature of a fast follower committed GE to
embracing the movement. It was GE who bridged the gap between just manufac-
turing process and product focus and took it to what was first called transactional
processes and later changed to commercial processes. One reason that Jack was so
interested in this program was that an employee survey had just been completed,
and it had revealed that the top-level managers of the company believed that GE
had invented quality, after all Armand Feigenbaum worked at GE; however, the
vast majority of employees did not think GE could spell quality. Six Sigma has
turned out to be the methodology to accomplish Crosby's goal of zero defects. Un-
derstanding what the key process input variables are and that variation and shift
can occur we can create controls that maintain Six Sigma, or 6 for short, perfor-

mance on any product or service and in any process. The Greek letter

σ

is used by
statisticians to indicate standard deviation, a statistical parameter, of the population
of interest.
Six Sigma is process oriented, and a generic process with inputs and outputs can be
modeled. We can understand clearly the process inputs and outputs if we understand
process modeling.

σ

7.4 INTRODUCTION TO SIX SIGMA PROCESS MODELING

Six Sigma is a process-focused approach to achieving new levels of performance
throughout any business or organization. We need to focus on a process as a system of
inputs, activities, and output(s) in order to provide a holistic approach to all the factors
and the way they interact together to create value or waste. Many products (including
software) and services, when used in a productive manner, also are processes. An ATM
machine takes your account information, personal identification number, energy, and
money and processes a transaction that dispenses funds or an account rebalance. A
computer can take keystroke inputs, energy, and software to process bits into a word
document.
At the simplest level, the process model can be represented by a process diagram,
often called an IPO diagram for input-process-output (Figure 7.3).
If we take the IPO concept and extend the ends to include the suppliers of the
inputs and the customers of the outputs, then we have the SIPOC, which stands for
supplier-input-process-output-customer (Figure 7.4). This is a very effective tool in
gathering information and modeling any process. A SIPOC tool can take the form of
a column per each category in the name.