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Process Capability Studies
Process Capability Studies: PPK, Process Performance Studies, CPK,
Controlled Condition Testing, Estimate of Process Variations, Predict Future
Capabilities
One function of Touchstone's Dimensional Inspection Lab is to conduct Process Capability Studies, designed to
determine what a manufacturing process is "capable" of doing under
controlled conditions.
There are actually two types of process studies that can be performed:
- Process Performance Studies
- Process Capability Studies
Process Performance Studies
Process Performance Studies are performed to identify how well a
process, statistically speaking, will perform over the long term.
For the Process
Performance Study to be successful the engineer performing the study must
check and
verify the following:
- Data is obtained over an extended period of time (at least 5
days of data) under normal conditions
- A minimum of 100 pieces in 20 subgroups of 5 is gathered -
statistical measurements taken to check for variations within each
subgroup and variations between the subgroups
A Process Performance Study allows you to determine "long" term stability and capability of a process. It is often used in the
early phases of a project to obtain an estimate of process variations when
only a small number of parts have been produced.
Process Capability Studies
Process Capability Studies, on the other hand, result from sampling
a continuous process over planned intervals.
- Studies look at how capable the process is, given ideal conditions,
over a short period of time, usually between one and twenty-four hours
- It is a prediction of what is likely to occur in the future based on sample subgroups taken over that period of time
- Allow you to determine "short" term stability and capability
of a process
A process capability study is performed for two primary reasons:
- Predict future capability of process to perform within
specification
- To identify process improvement opportunities
Process capability studies can help determine how much, if any, specimens are deviating from
specification, an important part of statistical quality control.
For a quote or more information about how we can help your project, call 765-454-5888, or send us an email, or submit this short form:
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