This part of ISO 10303 specifies the functional characteristics of a data access interface. This interface is referred to as the standard data access interface (SDAI). The SDAI specifies the operations available to an application for the purposes of acquiring and manipulating data whose structure is defined using ISO 10303-11 (EXPRESS).

The SDAI is specified in terms independent of any computing language or system. The specification of the functionality defined by the SDAI in a particular computing language is referred to as an SDAI language binding. SDAI language bindings are specified as companion documents within the implementation methods series of ISO 10303.

The following are within the scope of this part of ISO 10303:

• access to and manipulation of instances of entities described using the EXPRESS data specification language;
• access to multiple data repositories by a single application at the same time;
• capabilities for an application to organize operations into groups whose effect can be saved or cancelled at the discretion of the application;
• access to a dictionary describing the data elements that can be manipulated by an application;
• ability to invoke the validation of the constraints specified using EXPRESS at the discretion of the application;
• support for managing the dependency relationships between entity instances;
• capabilities to describe logical collections of entity instances that define the population over which entity instance to entity instance references are allowed;
• capabilities to describe logical collections of entity instances that define the population over which global rules are validated;
• support for the use of data created within the context of one schema in the context of another schema.

The following are outside the scope of this part of ISO 10303:

• the complete specification of the behaviour of an SDAI implementations in a multi-user environment;
• specific support for establishing a connection to a remote data repository;
• data access and manipulation operations that are specific to the semantics of the data;
• specification of the mechanisms or formats by which data is held in a data repository;
• creation, deletion, and naming of the data repositories available via the SDAI.