PDM-UG: Overview

From WikiSTEP

This page belongs to the PDM Usage Guide.

==Usage guide goal== to describe the recommended structure and attribute population for particular instance models created from the EXPRESS entities and types defined by the STEP PDM Schema. The selected instance models illustrate how to encode data values that need to be exchanged in support of key industry requirements common across the product manufacturing domain.

==Usage guide status== Release 4.3 covers the entire scope of the PDM Schema. The maintenance of this document is guided by the PDM Implementor Forum where issues and clarifications are raised and resolved. Issues may be put forward to the points of contact identified on the cover page of this document.

==Intended audience== developers of applications and information management systems that must use product data and exchange it with other systems and applications in support of the business processes related to product as_designed scope Anyone interested in the scope of the requirements supported by the STEP PDM Schema.

==Intended use== manual and companion to the developer of STEP data exchange and translator software used by applications and information management systems that rely on product data. Guideline for consistent preprocessor instance model creation and requirement value encoding to enable meaningful information exchange between different systems and applications using STEP. Guideline for consistent interpretation by a postprocessor of a STEP Part 21 exchange file according to the unified STEP PDM Schema.

==Usage guide style== overall document proceeds in an incremental, step-by-step fashion to describe, and in parallel to illustrate, the recommended instantiation of the EXPRESS entities and types in the PDM Schema.

The diagram figures are presented using a graphical notation intended to illustrate the instance model. This notation is not EXPRESS-G and does not illustrate the EXPRESS schema; rather it is a graphical illustration of a specific population of a particular instance model of the schema. This notation supports:

• illustration of entity instances,
• illustration and identification of referenced instances that are not fully illustrated in the current figure,
• illustration and identification of the multiple possible referenced instances corresponding to an attribute that has a select type as the value,
• indication of optional attributes and optional structure (dashed lines),
• illustration and identification of groups of functionally related instances (shaded bounding box),
• identification of specific attribute values (typically string values, may also be enumerated type values).

Each instance diagram figure is accompanied by a related STEP Part 21 exchange structure example. The example exchange file corresponds directly to the related instance model diagram and illustrates the very same thing using a different notation, i.e., STEP Part 21 syntax versus the graphical instance model notation.

==Usage guide structure== the overall scope of requirements is partitioned into a set of major sections corresponding to identified units of functionality. Within a major section, there may be sub-sections. These sub-sections further divide the scope into smaller components of coherent functionality that interact with each other to realize the functionality of the entire unit.

There is generally a description of requirements and a corresponding instance diagram associated with each section and sub-section of this document. Each instance diagram is followed by a detailed explanation and specific recommendations for the EXPRESS entities used in the instantiation diagram example. The entity listing and explanation is in turn followed by the corresponding STEP Part 21 exchange structure example.

Within a section, diagrams corresponding to sub-sections incrementally build upon one another to finally achieve a complete instance model example that illustrates the entire scope of the unit of functionality.