QUALITY PLANNING / PRACTICAL MANUFACTURING GUIDE
Define part tolerances and inspection requirements
Tolerances describe acceptable variation in specified features. Connect them to the part’s function, the approved drawing and a suitable method of checking the result.
Identify what controls function
Explain which features need to fit, locate, align, move or seal. Specify the relevant dimensions and relationships on the drawing. Tightening every dimension can add work without improving the intended function. Critical features need clear requirements, and ordinary features need an explicitly agreed general tolerance basis.
Use a controlled acceptance baseline
Identify drawing and model revision, units, material and finish. State the general tolerance convention and any feature-specific exceptions. Resolve conflicting requirements before production. The inspection team and manufacturing team should be using the same approved files rather than making separate assumptions about the design.
Define datums and checking conditions
A measurement depends on how the feature is located and assessed. Specify the relevant datums and clarify the part condition or assembly state when it affects acceptance. Mark whether dimensions apply before or after finishing. If a functional gauge or mating component defines the check, identify it in the inspection scope.
Select a suitable method
Callipers, micrometers, plug gauges, optical methods and coordinate measuring machines answer different questions. Review access, setup and instrument suitability against the feature. Instrument resolution or machine working range does not by itself establish measurement accuracy or an achievable part tolerance. Agree the method needed for the conformity decision.
Specify sampling and records
State whether the requested record concerns a first part, selected samples or another defined scope. Link reported results to part identification and drawing references. Request the report format, material records or additional tests that the project needs while the quotation is being prepared; they are not automatically included by a general quality statement.
Agree how discrepancies are handled
Retain the approved requirement, measured result and checking method if a part does not appear to conform. Include photographs or assembly evidence where useful. Agree the reporting process and keep affected items until the investigation and next action are decided. The record should show the actual result and disposition, not simply an unsupported “passed”.