Systems Modeling Language (SysML) 2.1 RTF — Open Issues - OMG Issue Tracker

Key: SYSML21-646

Status: open

Source: Northrop Grumman ( Mr. Steven Hetfield)

Summary:

For a product line revision (e.g. Rev E to Rev F of a Part Definition), it is extremely useful to identify the changes in characteristics (e.g. Attribute Usages) in terms of Subclassification (of the Part Def) and Redefinition (of its Attribute Usages).

The "validateFeatureValueOverriding" does not allow for Attribute Usages (as Features of a Part Definition) to have their quantity overridden by a redefinition. This would apply to Binding Connections, for sure, but not necessarily with the scenario shown below.

For example:

abstract part def CaseLarge_RevE :> Case {
    doc /* Cycling Computer enclosure for larger product line. Can be made in different colors.*/
    @CI {
        :>> PN = "50001206";
        :>> Rev = "E";
        :>> DwgName = "Case, Large";
    }
    constant attribute :>> mass [1] : Real = 69.8 [g];
    constant attribute colorOption :>> color : 'Color Options'::enum_CaseColor [1];
    constant attribute :>> length : Real = 114 [mm];
    constant attribute :>> width : Real = 58 [mm];
    constant attribute :>> height : Real = 19 [mm];
}
abstract part def <LgCase> CaseLarge_RevF :> '2026 Lineup'::CaseLarge_RevE {
    doc /* Cycling Computer enclosure for larger product line. Can be made in assorted colors, including an updated Red and, now, Royal Blue.*/
    @ CIInfo : CI {
        :>> PN = "50001206";
        :>> Rev = "F";
        :>> DwgName = "Case, Large";
        :>> ICD = "50001207, Rev B";
    }
    view 'Table_CI Information' : Table_CI {
        expose CaseLarge_RevF;
    }
    constant attribute :>> mass [1] = 67.5 [g];
    constant attribute :>> colorOption : 'Color Options'::enum_CaseColor_2027 [1];
    constant attribute :>> length : Real = 112 [mm];
}

The Rev F is intended to "be the same as Rev E", except the length and mass, which are redefined as shown. The redefinition makes it clear what has changed from Rev E to Rev F. However, this fails the "validateFeatureValueOverriding" validation unless "default" is used.

Using "default" is not as clear to stakeholders what the quantitative values are for attribute usages.

Reported: SysML 2.0 — Tue, 2 Jun 2026 12:23 GMT

Updated: Fri, 5 Jun 2026 20:13 GMT