msa中出现gage discrimination low要不要紧

发布网友发布时间：2022-04-26 10:36

共1个回答

热心网友时间：2022-06-27 10:42

gage discrimination low已经说明量具分辨率不够，首先要了解一个问题，做MSA前的量具分辨率要足够，否则做了也是多余的，在MSA手册中提到均值图中的点要至少50%要超出控制限，这样就说明分辨率足够和取样是代表过程或者产品的变差，如果当均值图中所有的点都超出控制限，那也说明取样存在问题，简单的取样方法是：中值取样3-4个，正负1/4公差取样各2，两极限值取样各1，或接近以上数值的样本，那你的均值图就能符合要求，望采纳！
Step 1Measurement Stability（R Chart by Operator）
A stable measurement system shows no out of control points or "non-random" patterns or trends in the range chart

Step 2Resolution / Discrimination（Xbar Chart by Operator）

Adequate resolution or discrimination means that the measurement units (inches, tenths of inches, thousandths of inches,…)
are sufficiently small enough to be able to "see" variation.
- Stratification on a range chart is a good indication that there is a problem with inadequate resolution.
- The number of stratified levels on the Range Chart is an indicator of the degree of the problem.
- Fewer "levels" means less adequate resolution:
- A rule of thumb: There should be approximately 5 levels of resolution between the control limits on the Range Chart and
less than 25% of the ranges equal to zero to be considered adequate.
Step 3Bias

Bias in a measurement study is a "shift" in the pattern on the X-bar chart between operators (i.e., the same part pattern is evident,
but one operator reads consistently higher or lower than the others).

Step 4Measurement Capability
Measurement capability is the comparison of Measurement Variation to Proct Variation to determine whether the current
measurement process can see part to part differences.
More than 50% of the part measurements should be out-of-control to be considered marginally acceptable.

Step 5Operator Bias
Operator Bias is the comparison of Between-Operator variation to Within-Operator variation. An out-of-control chart indicates that
a Bias does exist between operators, while a chart exhibiting control indicates that no Bias exists between operators.
Step 6Operator Inconsistency

Operator Inconsistency is the comparison of Within-Operator variation for a specific operator to the overall Within-Operator variation.
An out-of-control chart indicates that a Inconsistency does exist between operators, while a chart exhibiting control indicates that
no Inconsistency exists between operators.
Step 7Interclass Correlation & Discrimination Ratio

The major axis reflects proct variation, and the minor axis reflects measurement error.
The Discrimination Ratio is the ratio of the major axis to the minor axis.
DR >=5Gage appears to have adequate discrimination