ISO/TS 10303-1174:2005 specifies the application module for Class of activity library.

The following are within the scope of ISO/TS 10303-1174:2005:

• the existence of a class of activity;
• a mapping between one class of activity and another that indicates the nature of a whole-part relationship between two individual activities;
• a mapping between one class of activity and another that indicates the nature of a connection relationship between two individual activities;
• a mapping between a class of activity and a class that indicates the nature of an involvement in an activity;
• set theory relationships, such as subset, union and intersection, between classes of activity and between mappings.