Page 400 - Design for Six Sigma for Service (Six SIGMA Operational Methods)

360 Chapter Ten

material; information; money; and time can be mapped. Figure 10.11 shows
an example of a value stream map that maps not only material flows but also
the information flows that signal and control the material flows.

After a value stream map is developed, value-adding steps are identified for
each kind of flow, such as material and information flow. Non-value-adding
steps (waste), value inhibitors, costs of flow, and risks to flow are also
exposed, and their implications to overall process performance are analyzed.

After the problems in the existing process are identified by value stream
mapping, process revision or redesign can be initiated to eliminate the defi-
ciencies. In manufacturing processes, the revision can be made by elim-
ination of non-value-adding steps and redesign of the layout and sequence
of subprocesses, thus reducing cost and cycle time. In office processes, the
revision can be made by redesigning the organizational structure, reporting
mechanisms, building layout, and functional responsibilities of various
departments in order to reduce non-value-added steps and paperwork travel
time and mistakes, thus reducing waste and improving efficiency.
Based on the analysis, an ideal value stream map is created, in which all waste
and value inhibitors are removed, the cost and risk for flow are similarly reduced
to a minimum level, and we call it the ideal state. The full implementation of the
ideal state may not be feasible, but it often leads to a much-improved process.

The following is a case example of a value stream mapping project (Bremer
2002) which involves a manufacturing-oriented company. The companywide
information flow is illustrated by two value stream maps. The first map,
Fig. 10.12, shows how management thinks the information flows in this business;

Production
control

Supplier Manufacturer Distributor Customer

Note:
Information flow
Material flow
Figure 10.11 An Example of a Value Stream Map