The equation for Cp is often written ET / NT. ET stands for Engineering Tolerance, which is the width between the specification limits. NT stands for Natural Tolerance, which is the width that should contain almost all of the data from the process. Traditionally, NT is 6 times the standard deviation.
We often describe Cp as the capability the process could achieve if the process was perfectly centered between the specification limits.You may be mixing CPk and Cp.Hope this helps
-Evaluating finished product $50000
Clearly this is appraisal, not prevention.
-Quality auditor training $10000
Training is usually prevention, and especialy if it is quality realted training.
-Manufacturability study $1000
This is prior to production, and is related to preventing issues once in production. This is prevention.
-Repairing finished product $5000
Failure cost, either internal or external. Not a prevention cost.
-Process capability studies $30000
While these may occur during production in relation to a failure cost, capability is the comparison of specs to process spread. Most of the time these studies are related to insuring good quality, and so may be considered prevention.
$10000 + $1000 + $30000 = $41000
Hello Dhruva Bharucha,
See my comments in your message below.
Thank you! Is it true that when it comes to training/studies this is prevention. Thank you for the breakdown. For "Evaluating finished product" I would think this is prevention b/c you are taking extra steps to inspect and ensure the product is conforming to requirements. JW comment: Evaluating finished product is appraisal cost. Think about it; if it is already finished product, it is fully assembled and therefore any evaluation done to it cannot be preventive. But maybe I am mixing up evaluating versus inspecting.
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