Book Reviews

Engineering: The Missing Link in MRP

by Vincent C. Guess, copyright 1979, Vanard Lithographers

Reviewed by Sandy Friedman, CFPIM, CIRM

This book explores the foundations of what has become known today as Configuration Management (CM), or more recently, Configuration and Data Management (CM II), and Concurrent Engineering. Vincent Guess is a well-known authority on CM II, and is president of the Institute of Configuration Management. Here, he addresses the importance of communication between Engineering and Manufacturing, in support of maintaining accurate Bills of Material, not only for forward build, but also for logistics and field support activities. Guess presents his construction of the role of Engineering, from the classical stance to more progressive "Production Engineering" Departments, which foster a Concurrent Engineering approach to product development, delivery, and support by planning all facets of the engineering design up-front, at one time. This serves to decrease costs involved with release of subsequent Engineering Orders, and greatly shortens lead time from conceptual design to product shipment.

Configuration Management traditionally is found within Engineering/Data Management departments, especially within the Aerospace/Defense industry. The responsibility of CM is to manage the structure and format of the Engineering design process, and in some cases, to manage all downstream activities occurring after the formal release cycle of engineering documents, finally performing an "As Designed vs. As Built" reconciliation of the product against its engineering documents. Considering the context of the MRP II environment, these activities would include MBOM structuring and restructuring (for phantom or synthetic parts), purchase ordering of parts, fabrication and assembly of parts, delivery of products, and finally, product field support. In many cases, Configuration Management also defines part number - serial number traceability requirements, and calls for the capture of traceability as part of the "As Built" and "As Shipped" configurations for optimum field repair support. Accurate Configuration Management also increases control over engineering change cut-in points, especially if they must be performed on Work In Process (WIP) assemblies. Guess holds that control over the engineering-manufacturing Bill structure during each of these activities is essential for optimum capability and efficiency.

Guess describes Engineering's involvement in the Material Requirements Planning System ("MRPS" -- also known as MRP II -- Manufacturing Resources Planning -- today) as beginning with, logically, the engineering design. During the planning functions, the engineering design is translated into the Bill of Material, which specifies exactly the parts which are to be purchased or assembled. Resources required for fabrication or assembly are termed "Bill of Resources", while the steps to be performed in fabricating the part are called the Shop Order Job Routing, or more formally, the "Bill of Operations". Guess states that, "Product structuring is much broader in scope than BOM structuring... The Materials Management function and the production-related engineering functions are more interrelated and interdependent than manufacturing companies have formally acknowledged." Product structuring takes into account the MRPS functions, forecasts, and incorporates the Bill of Resources and Bill of Operations. A Bill structure must be constructed so as to afford flexibility; "The build process must be streamlined as much as possible in order to achieve minimum costs combined with optimum quality. The build process should maintain sufficient flexibility to accommodate changes". Guess continues, "The responsibility of structuring the product database in a manner which optimizes the master scheduling and the MRPS functions, however, has not been clearly identified. Engineering is generally assumed to be responsible for product structuring... which has little purpose unless it addresses the needs of the master scheduling function and also accommodates the factors required to achieve an effective MRPS." The Configuration of the product is ultimately impacted by sales forecast, firm sales orders, new product development, engineering changes, and customization, all of which affect the Engineering database.

Guess asserts that maintaining a tightly controlled Engineering Release and Configuration Management system is essential to remain competitive. "The manufacturer who can best execute and optimize huge rates of engineering changes and short lead time deliveries without sacrificing configuration control, traceability, inventory costs, obsolescence costs, etc., on a continuing basis will inevitably become the industry leader in that product market environment... Producibility refinements serve to reduce product costs and also to reduce the lead times for end product delivery capability." Functionally approaching "Concurrent Engineering" includes a team approach and the capability to recognize a continued need for refinement of both product and processes, thereby improving producibility.

Guess acknowledges the cultural challenges that must be overcome toward achieving what is called Concurrent Engineering today. "Product structuring is [typically] an Engineering function; the engineering activities in most manufacturing companies, however, have given minimum consideration to the needs of the production and inventory control functions." Guess asserts that product structuring, which is often divided between many organizations, must be developed as a single process with common MRPS goals. This may be achieved by relocating many of these functions such as Industrial Engineering, Manufacturing Engineering, etc., under one "Production Engineering" management structure.

In this book, Vince Guess presents some of the originating arguments in favor of a team approach to product design, as well as the foundations of Configuration and Data Management. Guess demonstrates the importance of recognizing Engineering as part of the MRPS engine, and how engineering design activities affect manufacturing, procurement, inventory management, and logistics functions. Cultural changes in the Manufacturing Industry are required and new management tools must be implemented to take advantage of the benefits proposed by Concurrent Engineering and CM II.