Process Control and Control Charts


Figure 10.2 Normal distribution. Source: PDA TR-59.5



Table 10.1


Significance of Cp


Image


image
Figure 10.3 Using a histogram of a CQA to produce a normal distribution curve. Source: www.moorestream.com.7

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

Only gold members can continue reading. Log In or Register to continue

Related posts:

  1. of PV
  2. Abstract
  3. 11
  4. Introduction

Stay updated, free articles. Join our Telegram channel
Tags:
Mar 4, 2017 | Posted by in PHARMACY | Comments Off on Process Control and Control Charts

Full access? Get Clinical Tree
Get Clinical Tree app for offline access