Hi Community,
we are using IFS Applications 10 Quality Management and Control Plans for dimensional inspections.
We have identified a limitation when defining variable characteristics with tolerance ranges according to ISO fits and tolerances, e.g. ISO 286.
In the standard functionality, IFS validates the tolerance values against the nominal value. For example, the following validations are applied:
- Outer Min must be less than or equal to the Nominal Value
- Inner Min must be less than or equal to the Nominal Value
- Inner Max must be greater than or equal to the Nominal Value
- Outer Max must be greater than or equal to the Nominal Value
This assumes that the nominal value is always located within the permitted tolerance range.
However, this is not always the case for standard engineering fits and tolerances.
Example: Ø20 s6
According to ISO 286, the tolerance zone is located completely above the nominal dimension. A characteristic can therefore have:
- Nominal Value: 20.000 mm
- Lower limit: 20.027 mm
- Upper limit: 20.040 mm
The valid inspection range is therefore 20.027 to 20.040 mm, while the nominal/basic size remains 20.000 mm.
Likewise, for tolerance zones below the nominal dimension, the complete permitted range can be below the nominal value.
From an engineering and quality-management perspective, the nominal/basic dimension and the tolerance limits are separate concepts. Therefore, the nominal value should not necessarily be required to be located between Outer Min and Outer Max.
We have already verified this in IFS Applications 10 by removing the corresponding nominal-value validations locally. After doing so, such characteristics can be represented while retaining the correct nominal value and the actual inspection limits.
Requested product enhancement
We would like IFS Product Management to consider removing or adapting these validations in the standard product so that variable Control Plan characteristics can support tolerance zones that:
- include the nominal value,
- are completely below the nominal value, or
- are completely above the nominal value.
The consistency between the lower and upper limits should of course still be validated. The requested change is specifically to remove the mandatory relationship between the nominal value and the tolerance range.
This would allow standard engineering tolerances and fits to be represented correctly in IFS Quality Management without a customization.
Is this limitation already known to IFS, or is there an existing solution/product enhancement for this requirement?
We would especially appreciate feedback from IFS Product Management regarding whether this behavior could be changed in the standard functionality.