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Before we establish a measurement requirement, we must first establish the quality requirement for the product or process. Example: A car door must open and close 1 million times without falling off it's hinges and it must stay where we put it and not bang us in the shins or open into traffic. We analyze these requirments and turn them into a design requirement. As part of this design requirement, we end up with performance limits or tolerances on components. These in turn must be measured and verified for a successful product or process output, ie defects per thousand, million, etc.
The measurement equipment used to verify the product or process performance limits/tolerances must meet it's own performance requirement over a given time interval,(accuracy and End-of-Period in-tolerance probability).
There is risk associated with a the measurement being made and this risk is passed onto the product or process in the form of scrap costs, rework costs and consumer rejection of the product.
Measurement risk can be defined as false accept consumer risk,(the percent probability the equipment is not within it's performance limits), rather than the nebulous 4:1 accuracy ratio.
How do you ask the customer (user) to define the measurement risk they can tolerate?
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The measurement equipment used to verify the product or process performance limits/tolerances must meet it's own performance requirement over a given time interval,(accuracy and End-of-Period in-tolerance probability).
There is risk associated with a the measurement being made and this risk is passed onto the product or process in the form of scrap costs, rework costs and consumer rejection of the product.
Measurement risk can be defined as false accept consumer risk,(the percent probability the equipment is not within it's performance limits), rather than the nebulous 4:1 accuracy ratio.
How do you ask the customer (user) to define the measurement risk they can tolerate?
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