How does STEP compare to alternatives?

To understand the advantages STEP offers it is useful to compare it to existing strategies and methods for sharing and storing technical data.

One possible approach is to standardize on a single system. On the surface, this is the simplest approach. In today's market, however, aerospace and defence suppliers typically deal with a number of clients and each of these may prefer to standardize on a different approach. A company could easily find itself using several proprietary formats in house with all the attendant problems of sharing, main-taining and storing data, as well as the cost of keeping staff trained in handling several systems.

Even when it is possible to exchange product data in native format between identical systems, there may still be value in using STEP. It opens doors for companies actively seeking new alliances by allowing them to share data with partners. It also allows an older version of a CAD system to read the design generated by the latest version of a CAD system. This is particularly important for companies working together with different versions of CAD, allowing each company to upgrade in its own time frame. It could also be of value if the CAD system processes of collaborating organizations are different, such as colour and layer mappings.

The advantages and return on investment of STEP-conformant tools will be greater when standard-ization on a single format is not an option. The ideal approach in such a situation is to store and transfer information in a neutral format such as STEP. This cuts down the number of translators required because each group sharing the data needs only to have software capable of translating between the format of the systems it uses and the agreed upon neutral standard.

STEP is not the only attempt to develop a neutral format. One possible alternative to STEP is the Initial Graphics Exchange Specification (IGES) standard, developed by the American National Standards Institute, which many businesses use to exchange data between dissimilar systems. In most commercial implementations, IGES addresses geometry. A recent version of IGES (5.3) includes electrical modelling capability and piping capability, although these features have not yet been tested. The current version of the standard is not practical for many applications involving electrical design and thin-walled entities such as pipes.

Some companies have "standardized" on proprietary graphical data exchange protocols, such as AutoCAD's Data eXchange Format (DXF). These data formats generally offer the capability to describe part geometry. Some, including DXF, offer simplicity, in exchange for a lack of rich features.

There is, however, an important and common difference between STEP and most other standards: the alternatives deal only with particular application areas and particular deliverables or products. STEP is intended to store all data for a product throughout its life cycle without regard to discipline or application area.

Integration is a distinguishing feature of STEP. No other standard currently offers this capability. Data integration ensures that the information describing product design, manufacturing and life cycle support is defined only once. STEP data integration eliminates redundancy and the problems caused by redundant information. Standards that do not have this integration capability provide benefits only if the data are reused. On the other hand, STEP data integration is an important advantage, even if the data are never exchanged.