Process Capability Analysis
Assignment-1
Process Capability Analysis
Objective
To apply Process Capability Analysis model for Six Sigma implementation in telecommunication area.
Important Concepts
Process capability compares the output of a process to the specification limits by using capability indices. The comparison is made by forming the ratio of the spread between the process specifications.
Process Capability Indexes:
Cp is a process index that helps in numerically describing variation relative to the tolerances or specifications. Cp is a short term process index that describes the "within subgroup" or "potential" capability (Pp is long term indicator) of a process assuming it was analyzed and stays in control. Cp should always be analyzed with Cpk, as Pp should always be analyzed with Ppk. The Cp has no value for unilateral tolerances. Unilateral means that only the LSL or USL is provided, the calculation of Cp requires both specifications.
Cpk is a short term process index that numerically describes the "within subgroup" or "potential" capability (Ppk is long term indicator) of a process assuming it was analyzed and stays in control. As with all the process capability indices, the process should be in control before assessing capability.
Cpm is a capability index, also known as the Taguchi capability index that is a function of the specification limits, mean of the process, and a provided target, T. The indices of Cpk and Ppk focus on centering of the mean of the distribution around the midpoint of the tolerances (USL+LSL/2) but this is not always the customer target. Sometimes the customer may specify targeting the upper or lower end of the tolerance. This could be due to past experiences, part weight reduction, and many other reasons.
Pp is a process index that numerically describes the long term capability (Cp is short term indicator) of a process assuming it was analyzed and stays in control. As with all the process capability indices, the process must be in
Process Capability Analysis
Objective
To apply Process Capability Analysis model for Six Sigma implementation in telecommunication area.
Important Concepts
Process capability compares the output of a process to the specification limits by using capability indices. The comparison is made by forming the ratio of the spread between the process specifications.
Process Capability Indexes:
Cp is a process index that helps in numerically describing variation relative to the tolerances or specifications. Cp is a short term process index that describes the "within subgroup" or "potential" capability (Pp is long term indicator) of a process assuming it was analyzed and stays in control. Cp should always be analyzed with Cpk, as Pp should always be analyzed with Ppk. The Cp has no value for unilateral tolerances. Unilateral means that only the LSL or USL is provided, the calculation of Cp requires both specifications.
Cpk is a short term process index that numerically describes the "within subgroup" or "potential" capability (Ppk is long term indicator) of a process assuming it was analyzed and stays in control. As with all the process capability indices, the process should be in control before assessing capability.
Cpm is a capability index, also known as the Taguchi capability index that is a function of the specification limits, mean of the process, and a provided target, T. The indices of Cpk and Ppk focus on centering of the mean of the distribution around the midpoint of the tolerances (USL+LSL/2) but this is not always the customer target. Sometimes the customer may specify targeting the upper or lower end of the tolerance. This could be due to past experiences, part weight reduction, and many other reasons.
Pp is a process index that numerically describes the long term capability (Cp is short term indicator) of a process assuming it was analyzed and stays in control. As with all the process capability indices, the process must be in