Process Control and Control Charts

Figure 10.2 Normal distribution. Source: PDA TR-59.5

Table 10.1

Significance of Cp


Figure 10.3 Using a histogram of a CQA to produce a normal distribution curve. Source:

Cp=Process Capability.

Cpk=Process Capability Index. This adjusts the Cp for the effect of noncentered distribution.

Pp=Process Performance.

Ppk=Process Performance Index. This adjusts the Pp for the effect of noncentered distribution.7

In looking at a graphic representation Fig. 10.47 shows the results of different levels of Cp. Note that with a Cp of less than 1 the production is very spread out within the set limits. While a Cp value >1 shows a very tight fit of all data points. Another way of looking at it and interpreting the results of the calculations is:

Here we are looking at the fit within a door frame (set limits)9

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Mar 4, 2017 | Posted by in PHARMACY | Comments Off on Process Control and Control Charts

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