Statistical Process Control (SPC)
Statistical Process Control (SPC) is the term used to cover the application of statistics to the control of industrial processes.
Statistics used to monitor the process include:
- mean
- range
- standard deviation
- histogram
- control chart
- capability
- six
Consider the statistic derived from inspecting a batch of 500 components by picking 50 components from a box of 500 and measuring them.
The statistic derived from those measurements – such as the average size and the standard deviation of the sample will allow acceptance or rejection of the batch depending on the sampling plan that you have selected and the particular criteria used.
However, sampling in this way will not say a great deal about the manufacturing process.
Change the inspection process to one where every tenth component off the production line is measured and the average size, standard deviation and trends can be determined.
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Good practice online modules
- Dimensional
- Overview of basic design & interpretation of an engineering drawing
- An introduction to datum
- An introduction to geometric tolerancing
- An introduction to the designer's role in the design & interpretation of an engineering drawing
- An introduction to the manufacturer's role in the design & interpretation of an engineering drawing
- An introduction to the inspector's role in the design & interpretation of an engineering drawing