This part of ISO 13584 specifies the principles that shall be used for defining families of parts and properties of parts to fully characterize parts and associated properties.

The rules and guidelines provided in this part of ISO 13584 are mandatory for the standardisation committees responsible for creating standardised identification hierarchies.

The use of these rules by suppliers and users is recommended as a methodology for building their own hierarchies.

The following are within the scope of this part of ISO 13584:

• the rule to group parts into generic families of parts and simple families of parts;
• the rules for the choice of the appropriate properties that shall be associated with the families of parts;
• the attributes that shall be provided by library data suppliers to describe the families and properties of parts.
• the specifications of those attributes in the EXPRESS information model that provide for the exchange of such dictionary data.

The following are outside the scope of this part of ISO 13584:

• libraries of assembled parts with aggregate structure (Level 3 libraries);
• the description of the parts themselves;
• the descriptions of the functional models that may refer to some family of parts;
• the description of tables, program libraries and documents that may refer to some family of parts;
• the description of the systems intended to manage parts libraries; and
• the EXPRESS resource constructs for references between libraries.

The structure of the information and the methodology defined in this part of ISO 13584 enable the following:

• integration in the same data repository of different parts libraries originating from different library data suppliers with an uniform access mechanism provided by a dictionary;
• integration in the same data repository of different definitions of materials originating from different suppliers with an uniform access mechanism provided by a dictionary;
• referencing another supplier library assumed to be available on the receiving system;
• referencing a standardised identification hierarchy when such a hierarchy exists;
• definition by an end-user of a local classification or search hierarchy, and the mapping of these hierarchies onto the supplier libraries available on its system.