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Reuse Methodology and Implementation Appnote

1.0 Introduction

In today's engineering design environment, designers are limited in their ability to maximize reuse by the fact that there is no efficient way to search for, access, and integrate reusable design objects across multiple sources; frequently, these potential sources of reusable design data are uncoupled from the design environment. Also lacking are mechanisms and processes for organizing reusable design information created within a design team, and for effectively sharing that design knowledge within the organization as well as with other cooperating organizations

No two product data management (PDM) system implementations are alike, though up to 90% of the underlying database schema may be generic, for example. Every local design organization has their own classification scheme for designs developed internally, even in cases where the use of a single software product, such as the Metaphase Product Data Management System [SDRC_1997], which provides the configuration management functionality for the RASSP Enterprise Environment, has been mandated by a corporate engineering process improvement directive. Integration of multiple instances of the Metaphase system is possible in cases where the classification scheme is the same for all instances, but not easily otherwise. Costly, unique point-to-point integration is required in most cases where multiple applications and databases are involved today.

We describe in this paper an approach for integrating multiple, diverse sources of engineering and business data to provide a single entry point for searching for reusable design knowledge and to enable collaborative engineering throughout the enterprise. This approach was developed and prototyped for the DARPA Rapid Prototyping of Application-Specific Signal Processors (RASSP) program.

The Rapid Prototyping of Application-Specific Signal Processors (RASSP) is a Defense Advanced Research Projects Agency (DARPA)/Tri-Service program aimed at dramatically improving productivity in the design, manufacture, test, and procurement of digital signal processors. RASSP products include an enterprise system, which integrates the CAD tools used in the RASSP design process, workflow tools for managing the design process, and the tools for managing the design data. Reuse data management in the RASSP system involves the generation, organization, distribution, and use of reusable design knowledge. Sources of reusable designs in the RASSP environment may include those created within an engineering design organization, CAD tool libraries, CAD tool-independent libraries, released designs managed by product data management (PDM) systems across the enterprise, related business and engineering information, and component vendor data, among others.

Key aspects of our approach for reuse data management include:

This approach was applied to the satellite communications domain, relevant to the Lockheed Martin Astrospace company in Newtown, PA, and to the integration of multiple VHDL model repositories developed by several organizations associated with the RASSP program. Two prototype implementations of the RASSP Reuse Data Manager (RRDM) were created for the satellite communications application, both of which included a web-based front-end to the reuse repository. The early prototype stored all meta-data as text in HTML files, while the second uses an object-oriented database engine for persistent storage of both the common vocabulary and reusable design knowledge. Both demonstrated subsets of the target features of the RRDM. The VHDL model demonstration extended the original RASSP reuse classification hierarchy (RRCH) to support many types of VHDL models and related design data. The extended RRCH is compliant with the RASSP VHDL Modeling Terminology and Taxonomy recently adopted by the VHDL user community. Based on lessons learned from the prototype implementations we have further refined the architecture and concept of operations for the RRDM. The underlying technology of the RRDM was developed and is being commercialized by Sandpiper Software, Inc., with partial funding from the RASSP program.

In the next section we describe the architecture of the RASSP enterprise system, and the role of the RRDM in that environment. In section 3 we describe the processes and methodology developed on the program that are specific to integrating new or modified designs with the reuse system and accessing those designs for use in new applications. In section 4 we present a knowledge-based approach for modeling the RASSP domain as well as components of the resultant RASSP reuse classification hierarchy. In section 5 the high-level architecture of the RRDM and its concept of operations is discussed. An application of the RASSP reuse methodology at an operating company and the RRDM prototype demonstrations is the subject of section 6. Section 7 details the key benefits and implications of the technology developed, provides some comparisons with related technologies, and summarizes the significant lessons learned.

next up previous contents
Next: 2 Architecture of the RASSP Enterprise System Up: Appnotes Index Previous:Appnote Reuse Index

Approved for Public Release; Distribution Unlimited Dennis Basara