CHAPTER IV

STATISTICAL PROCESS CONTROL

* This chapter covers two topics that are increasingly important in business organizations: quality control and continuous improvement. * Quality control focuses on the conversion of inputs into outputs. * The purpose of quality control is to assure that processes are performing in an acceptable manner.

* This is accomplished by monitoring process output using statistical techniques.

* If the results are acceptable, no further action is required; unacceptable results call for corrective action.

* In the best companies, the emphasis is on designing quality into the process, thereby greatly reducing the need for inspection or control efforts.

-As you might expect, different business organizations are in different stages of this revolutionary process: * The least progressive rely heavily on inspection. * Many occupy a middle ground that involves some inspection and a great deal of process control. And the most progressive have achieved an inherent level of quality that is high enough that they are able to avoid wholesale inspection activities as well as process control activities. That is the ultimate goal. Figure 4-1 illustrates these phases of quality assurance.

Figure 4-1 Phases of quality assurance
Acceptance
Sampling
Inspection before/after production
Corrective action during production
Quality built into the process process
Acceptance
Sampling
Inspection before/after production
Corrective action during production
Quality built into the process process

Continuous improvement
Process
Control
Continuous improvement
Process
Control

The least progressive
The least progressive
The most progressive
The most progressive

* Quality assurance that relies primarily on inspection after production is referred to as