STEP

Standard for the exchange of product model data

The DiK has supported the development of the application protocol (AP) 214 significantly, which describes the development process for the automotive industry.

From the beginning the development of STEP was one of the main topics. STEP (Standard for the Exchange of Product model data) describes the international standards being published in the series of standards ISO 10303. In 1984 the STEP activities began with the goal to develop an international standard being able to detect all the neutral information for the whole product life cycle which a computerised product modell contains, without loosing integrity.

The architecture of STEP is aimed at supporting the development of standards for the exchange and the common use of product data. The separate components of this architecture are refelected in the segmentation of standards in seperate documents (parts), which are combined to groups. Basically the STEP document architecture consists of 'description methods' (e.g.. specification of the data modelling language EXPRESS), 'Implementation Methods' (e.g.. physical file), 'Integrated Resources' describing the integrated product modell and the application protocol specifying data models in a certain apllication context.

The methodology of the development for all application protocols (AP) follows a standardised methodic proceeding, devided in four phases:

  • process analyse,
  • modelling of requirements
  • interpretation and
  • implementation.

The development of an application protocol always beginns with the analysis of processes. The required processes in an application context have to be identified and analyzed. By describing the processes, AAM (Application Activity Model) is achieved. In the phase of modelling requirements, experts specify the ARM (Application Reference Modell) in EXPRESS und EXPRESS-G for process and data modelling.

The next step of the AP development process is the so-called 'mapping'. This means that the reference modell is mapped on the integrated data modell of STEP. The result of the 'mapping' is the AIM (Application Interpreted Model).

Originally only implementations of the 'neutral' AIM modell were resolved. Due to the tremendous effort of the 'mapping'. more and more implementations of the ARM are resolved.

STEP@DiK

Several research assistants took over the role of the 'part editors' for the AP document and supported the development process as experts for data modelling. In 2001 the first version of AP 214 was released by ISO as an international standard. After a revision, in which about 200 reported complaints were dealt with, a second version was released in 2003. Both versions are offered together with a HTML document, which is completely linked and includes the entire content of the standard.

Next to the standardisation on ISO level in the STEP environment, the 'MechaSTEP' project was funded in the framework of 'production 2000' by the German government department for education and research. (BMBF). The result of this project was the specification of a neutral data format for data exchange between application software for the development of mechatronical products. Data from the fields of electronics, hydraulics, pneumatics, automation und mechanics are being considered. The MechaSTEP data modell consists of data being specified in the seperate fields and was released as DIN PAS 1013 in 2002.