ST: On an R&R study, if I use the specifications, the study is good. If I use the study parameters, the gage fails
...
In AIAG's Measurement Systems Analysis manual, the standard approach for R&R percentages is to use percent of study variation. This means that the parts selected for the study ...
- ST: How do we determine process capability if the process isn't normal
...am. Therefore, we generally make the assumption of the normal distribution in order to estimate the percent out of specification (above, below, and total).
For non-normal distributions, we first es...
- ST: Uncertainty Study
...ract the reference value to give an average bias value.
If you would like the bias expressed as a percent of specification or percent of process variation, you enter the USL, LSL and/or six sigmas f...
- ST: How do you interpret an R&R Study?
...ommon here is the AIAG (Automotive Industry Action Group) standards, which are based on the R&R percentage given under study results. These results may be calculated as a percent of study variatio...
- ST: Chi Square and Confidence
...should not be treated as normal. In general this means that using the normal to figure theoretical percentages out-of-spec is incorrect. If there is sufficient data, the out-of-spec can be estimated ...
- ST: What is the difference between the attribute and variable sampling plans?
...e), and enumerative sampling tries to determine something about an existing population (what is the percent bad in the shipment just received, for example). You need to determine the purpose for takin...
- ST: 4.5.3. Determining the total percentage outside the specifications
Revision Date: 2005-09-07
The total percentage outside the specification limits or requirements is found by adding the percentage outside the upper and lower specification limit...
- ST: 4.3. Determine the location of the tails for the distribution
...tribution, plus or minus three times the standard deviation from the overall average includes 99.73 percent of the area under the curve. The calculation for the location of the left tail is:
For ...
- ST: What kind of set-up would you recommend for testing one instrument?
Revision Date: 2005-09-06
Problem:
It measures percent acidity. There are six analysts who use the instrument to test acids whose strengths range from 50% to nearly 100%. I could have each analyst...
- ST: 4.5.1. Find the percentage above the upper specification
Revision Date: 2005-09-07
The first step in determining the percentage above the upper specification is to calculate the Z value for the upper specification. This is found ...
- ST: 4.6.1. Calculate Cp
...estimated standard deviation. Plus or minus 3 times the estimated standard deviation contains 99.73 percent of the data and is commonly used to describe actual spread.
Cp for the example is:
...
- SP: SQCpack - Making it your own
...ith histograms (perhaps mean, estimated sigma, calculated sigma, Cpk, Ppk,Cpm, Dpm, and theoretical percent out-of-spec), you should create your own histogram defaults.
To set defaults, start SQCpac...