External Representation of Product Data:
AP-203 and AP-224 provide the essential capability for low-cost generation of mechanical parts CAD/CAM models and quick transfer of the vector data between disparate CAD/CAM systems. STEP's transfer capabilities shall result in creating more private sector competition for manufacturing weapons systems components, that means many 2nd and 3rd tier parts manufacturers shall not bid on a job if the vector data are not compatible along with their CAD/CAM system. DoD have to develop a strategic plan for capturing this manufacturing benefit, particularly for its legacy systems where the technical data reside in a extensive variety of formats if, actually, they exist.
A general complaint voiced in the end item management and DoD parts manufacturing communities is that no technical data for various repair parts exist, particularly for some of those weapons systems procured using the performance specifications method of acquisition. Engineering data tend to become a lost child in the acquisition, merger, and business failure environment of the private sector economy. It is expensive to reengineer a part, but i.e. the only solution remaining once the technical data are lost. Though, the combination of AP-203 and AP-224 provides a low-cost redemption alternative for mechanical parts.
The STEP (Standard for External Representation of Product Data) project is supported through the ISO workgroup TC 184/SC4. This is also sometimes called as Standard for Exchange of Product Definition Data. This is an effort by this group to build up an international standard for representing product model & a data exchange is a series of standards intended to give a common mechanism for representing product model data during the life-cycle of a product independent of any application software that might be utilized to process it. The fundamental principles of STEP are illustrated in Figure. The figure illustrated a computer-integrated manufacturing system where CAD data is strongly coupled using the STEP interface to the major production activities such like CAP, PP and C, CAM and CAQ. STEP shall be replacing the mostly the standards developed so far above. The series of standards in STEP provide a neutral representation of product model data in the form of a set of integrated resources that support a total and unambiguous definition of a product. The resource constructs are documented in a single product data language definition as explained in Mason (1991).