Business Object Design and Implementation Workshop

Position Paper

Experiences With a Manufacturing Framework

Seldon L. Stewart and James A. St. Pierre (selden@nist.gov)

Organization

Date/Place: 16 October 1995/Austin, TX

Introduction

We are halfway through a three-year joint project with SEMATECH on a Computer-Integrated Manufacturing Framework (CIMF). The results of the first year of that project are reported in: Roadmap for the Computer-Integrated Manufacturing (CIM) Application Framework, available as http://elib.cme.nist.gov/msid/pubs/stewart95a.pdf (or .ps) and from SEMATECH in hardcopy as Tech Transfer 95052825A-ENG. The purpose of this project is to promote and standardize a general, object-oriented framework for manufacturing. Business objects are a very broad class, of which manufacturing objects are only a part. However, manufacturing plays a major role in the economy. Every business is a consumer of manufactured products, and many businesses are in manufacturing. As a result it is important that a CIM framework be closely integrated into any larger business or enterprise framework.

Successful integration is based on well-defined and widely accepted interfaces. Thus the object-oriented approach with its emphasis on interface specification is well adapted to integration. Unfortunately, specification of interface signatures, as with CORBA/IDL, is only a necessary but not sufficient condition for integration to be successful. The more difficult question is how to specify what an interface does, without overly constraining possible implementations. We suggest that this is significant problem for this workshop to address.

Stages of Development for a Framework

In our report we defined for stages of development for a framework:

• Developing a Specification
• Reaching Consensus
• Standardization
• Testing and Certification

These stages are in logical order, but generally their execution will overlap to a large degree. Results from any one stage will feed both backwards and forwards to the other stages. We also developed recommendations for how to carry out such a program. While some of the recommendations are quite specific to the project at hand, many can be restated for more general frameworks. Here are recommendations that we believe might be applicable to a wide range of business application frameworks.

• Adopt a single source electronic specification management approach
• Involve users and suppliers in both specification and certification development
• Give reference implementation high priority
• Make the interface between client and server objects neutral
• Reach consensus on certification business model and methodology
• Address the high cost of certification
• Develop usage scenarios to clarify implementation and use of the framework
• Leverage other specifications, especially CORBAfacilities and CORBAservices
• Do not make certification dependent on access to suppliers' source code
• Focus on interoperability
• Expand use of formal description techniques in the specification
• Explore automatic test generation
• Require suppliers to provide certification tests for any extensions they add

These are recommendations based on our experience studying one framework in a particular application domain. However, the framework is large and manufacturing is a significant application domain.

Question for the Workshop

What are good ways to specify the semantics (the "what") of an interface without overly specifying the details of the implementation (the "how")?

Business Object Design and Implementation

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