Lock part default unit of measure on BOM

Before editing a system rule, ensure that no other users are using the system. After editing a system rule, restart your PDXpert client application.

To prevent unit of measure conversion errors in MRP exports and roll-up reports, this rule is a one-time setting. If this rule is saved as False, then it cannot be reset as True. If your other software, such as MRP system, requires default units of measure on the BOM, keep the rule setting as True.


Ensures that a part's default unit of measure is always used on a bill of materials (BOM).


True: Every BOM uses the Default unit of measure that's been defined on the part's Attributes tab. This assignment cannot be edited on the BOM.

False: The unit of measure defined on a part can be overridden with a compatible unit of measure on a BOM markup. For example, a part with a default unit (for example, length cm) can be added to a BOM markup, and then be re-specified with a compatible unit (say, mm or inch).

While this rule is False: If you change a part's default unit of measure, use the part's Appears On list to verify that the quantity and unit of measure is correct on each BOM.

Data type


Recommended or default value



Provided that downstream systems can accept varying units, setting this rule to False gives users greater freedom to specify units of measure on assembly BOMs.


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