3.
Production
Process Characterization
3.1. Introduction to Production Process Characterization 3.1.3. Terminology/Concepts


Distributions are characterized by location, spread and shape  A fundamental concept in representing any of the outputs from a production process is that of a distribution. Distributions arise because any manufacturing process output will not yield the same value every time it is measured. There will be a natural scattering of the measured values about some central tendency value. This scattering about a central value is known as a distribution. A distribution is characterized by three values:  


A primary goal of PPC is to estimate the distributions of the process outputs  One of the primary goals of a PPC study is to characterize our process outputs in terms of these three measurements. If we can demonstrate that our process is stabilized about a constant location, with a constant variance and a known stable shape, then we have a process that is both predictable and controllable. This is required before we can set up control charts or conduct experiments.  
Click on each item to read more detail 
The table below shows the most common numerical and graphical measures
of location, spread and shape.
