What is STEP?

STEP is an acronym which stands for the STandard for the Exchange of Product model data. STEP is a part of the International Organization for Standardization (ISO) and its formal name is ISO 10303: Industrial automation systems and integration -- Product data representation and exchange. It was developed by ISO TC184/SC4 (Industrial data).

With 28 nations participating or observing, STEP is a worldwide effort to develop a mechanism for the exchange and sharing of engineering data. STEP works towards neutral industrial data definitions, representation, and language that supports life cycle functions. The use of a common exchange format will help reduce translation costs and improve quality throughout the use of the data. STEP will enable product data sharing between software applications throughout a product life cycle, different organizations involved in a product life cycle, and physically dispersed sites within an organization.

Some examples of commercial implementations of STEP can be seen in the digital pre-assembly of Boeing 777, and General Motors exchange of part designs with its suppliers.

Terminology

Abstract Test Suite

"The Abstract Test Suite specifies ... the test cases that will be used in assessing the conformance of an implementation to the data specification contained in an AIM and the other elements of the STEP architecture upon which an AIM depends." (Fowler, Julian. STEP Development Methods, March 7, 1995, p.7.)

Application Activity Model (AAM)

A part of an Application Protocol. The AAM " ...supports the analysis of the activities and information flows within the scope of the industry application. ..." (Fowler, Julian. STEP Development Methods, March 7, 1995.)

Application Interpreted Model (AIM)

A part of an Application Protocol that explains the context (scope) and meaning (relationships) of the data to be exchanged (How). "The AIM fulfills the requirements stated in the ARM through selection and constraint of standard data constructs ... [It]specifies the data constructs to be used in achieving exchange of information between computer applications ..." (Fowler, Julian. STEP Development Methods, March 7, 1995, p. 5.)

Application Protocol (AP)

An Application Protocol defines the usage of STEP product data for a given application context. An AP is the implemented information exchange part of STEP and defines industry information requirements, specifies the structure of the exchanged data elements in an application context, and specifies the basis for conformance testing of software implementations. An Application Protocol represents a measurable and shareable subset of STEP capability that is expressed in an industry's or discipline's terminology.

Application Reference Model (ARM)

A part of an Application Protocol that defines the user requirements view (What). The ARM is a " ... detailed specification of the data objects (entities and attributes), and the relationships between them, that are required to support the activities within the scope of the industry application." (Fowler, Julian. STEP Development Methods, March 7, 1995, p. 5.)

Conformance Classes

A part of an Application Protocol that defines different exchanges that are allowed, their purpose and expected data content (Why). "A conformance class defines a subset of the AIM that may be used as the basis for implementation and testing." (Fowler, Julian. STEP Development Methods, March 7, 1995, p.6.)

Integrated Resources (IRs)

The Integrated Resources "are data models that reflect and support the common requirements of many different product data application areas." (Fowler, Julian. STEP Development Methods, March 7, 1995.) "Contained in these models are the standard data constructs used in the creation of the AIM." (Fowler, Julian. STEP Development Methods, March 7, 1995, p. 6.)

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Last Updated: August 12, 1999