3.1. Introduction to Production Process Characterization
|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.