ssp responsible-roles vs responsible-parties

[paulJRCurtis]

In the ssp [control-implementation][implemented-requirements] there is a responsible-roles object with the same properties as the responsible-parties object in metadata. There are similar examples across other models - quite a few in the assessment layer.

I'm writing reusable components and it would be great to understand if there is there a reason for the different names?

[GaryGapinski]

(Edited to correct cardinality error on responsible-party/party-uuid — is {1,∞}.)

I hadn't previously noticed this. They are almost identical except for the element name and child element order. I am uncertain why both exist. Each has a disjoint set of venues "relative to the containing object". Both declare one role and allow optional association to party without limit. Since role ⇄ party association can also occur using metadata/responsible-party this allows for semantic uncertainty among such associations (metadata/responsible-party, elsewhere/responsible-role, elsewhere/responsible-party). Both are role ⇄ party associations.

responsible-role is described as "A reference to one or more roles with responsibility for performing a function relative to the containing object.". That definition is incorrect, as there can only be one role reference (@role-id is not multi-valued).
Has a single required attribute role-id.
Allows elements

1. prop {0,∞}
2. link {0,∞}
3. party-uuid {0,∞}
4. remarks {0,1}

(in that order — all are optional).
Occurs in

• oscal-component-definition-defined-component-ASSEMBLY {0,∞}
• oscal-component-definition-implemented-requirement-ASSEMBLY {0,∞}
• oscal-component-definition-statement-ASSEMBLY {0,∞}
• oscal-implementation-common-system-component-ASSEMBLY {0,∞}
• oscal-ssp-implemented-requirement-ASSEMBLY {0,∞}
• oscal-ssp-statement-ASSEMBLY {0,∞}
• oscal-ssp-by-component-ASSEMBLY {0,∞}
• oscal-assessment-common-activity-ASSEMBLY {0,∞}
• oscal-assessment-common-task-ASSEMBLY {0,∞}

responsible-party is described as "A reference to a set of organizations or persons that have responsibility for performing a referenced role in the context of the containing object." 

Has a single required attribute role-id. Allows elements

1. party-uuid {1,∞}
2. prop {0,∞}
3. link {0,∞}
4. remarks {0,1}

(in that order).
Occurs in

• oscal-metadata-metadata-ASSEMBLY {0,∞}
• oscal-implementation-common-inventory-item-ASSEMBLY {0,∞}
• oscal-ssp-system-characteristics-ASSEMBLY {0,∞}
• oscal-assessment-common-assessment-assets-ASSEMBLY {0,∞}
• oscal-assessment-common-related-task-ASSEMBLY {0,∞}
• oscal-ar-result-ASSEMBLY {0,∞}

[CyberDaedalus00]

If you check cardinality of the party-uuids field in responsible-party, you'll see that it requires at least one party, where the cardinality of the party-uuids field in responsible-role is that the party-uuids is optional .

[GaryGapinski]

@CyberDaedalus00 is correct. I had the party-uuid cardinality wrong in responsible-party. I will edit my response.