Page 59 - Design for Six Sigma a Roadmap for Product Development

36 Chapter Two

Step 2: Identify and document the process
1. Identify the process. In a Six Sigma process improvement project,
usually a team works on one process at a time. The process being
identified is usually
■ A core process in the company, such as product development, mar-
keting, or customer service, so it is a very important process for
the company
■ A support process, such as a human resource or information sys-
tem, but this process becomes a bottleneck or a waste center of
the company
2. Document the process. After a process is identified, an appropriate
process model will be used to model and analyze the process, such
as a P-diagram model or a SIPOC model.

After the process model is determined, the major elements of process
model, suppliers, inputs, process map, process output, and customer
base should be defined. In this step, we will only stay at the top-level
process model, or at most one level lower, because we do not want to be
buried in details at the beginning.

Step 3: Identify, analyze, and prioritize customer requirements

1. Identify customer requirements. There are two kinds of customer
requirements:
■ Output requirements. These are the features of final product and
service delivered to the customer at the end of the process. For
example, if the output voltage of a power supply unit is 6 V, the
output requirement in the customers’ eyes could be “Voltage
should not be neither too high nor too low.” The numerical
requirements could be expressed as “between 5.5 and 6.5 V.” For
a complicated product or process, such as an automobile or a
power plant, the list of outputs and its related requirements could
be very long.
■ Service requirement. These are the more subjective ways in
which the customer expects to be treated and served during the
process itself. Service requirements are usually difficult to define
precisely.
2. Analyze and prioritize customer requirements. The list of customer
requirements could be very long for a complicated product or
process and is often hierarchical. For example, there could be many
customer requirements for an automobile, such as drivability,
appearance, and comfort while driving. For drivability, it could
include many items, such as acceleration, braking performance, and