ASTM F 1503 : 2002 : R2012
Withdrawn
A Withdrawn Standard is one, which is removed from sale, and its unique number can no longer be used. The Standard can be withdrawn and not replaced, or it can be withdrawn and replaced by a Standard with a different number.
Standard Practice for Machine/Process Capability Study Procedure (Withdrawn 2018)
Hardcopy , PDF
21-06-2018
English
01-10-2012
Important note : Users cannot be edited or removed once added to your Multi user PDF.CONTAINED IN VOL. 01.08, 2017 Covers provision of a proper method for determining process capability for new or existing machine processes.
| Committee |
F 16
|
| DocumentType |
Standard Practice
|
| Pages |
4
|
| ProductNote |
Reconfirmed 2012
|
| PublisherName |
American Society for Testing and Materials
|
| Status |
Withdrawn
|
| Supersedes |
1.1This practice covers provision of a proper method for determining process capability for new or existing machine processes. It is recommended that available statistical software be used for the calculation of the descriptive statistics required for decision making when using this practice. Where software is not available, Section 8 and Tables 1 and 2 are provided for manual calculations.
| Calculate the average Range (R) and the Process Average X For the study period, calculate: | |
| where: | ||
| k | = | the number of subgroups, |
| R1 | = | the range and average of the first subgroup, |
| X1 | = | the range and average of the first subgroup, |
| R2 | = | from the second subgroup, and |
| X2 | = | from the second subgroup, etc. |
| Estimate the process standard deviation (the estimate is shown as σ^ “sigma hat”). | |||||||||
| Using the existing sample size calculate: | |||||||||
| σ^ = R/d2 | |||||||||
| Where R is the average of the subgroup ranges (for periods with the ranges in control) and d 2 is a constant varying by sample size, as shown in the table below: | |||||||||
| n | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| d2 | 1.13 | 1.69 | 2.06 | 2.33 | 2.53 | 2.70 | 2.85 | 2.97 | 3.08 |
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