DETERMINING FUNCTIONAL REQUIREMENTS FOR NASA GODDARD'S COMMAND MANAGEMENT SYSTEM SOFTWARE DESIGN USING EXPERT SYSTEMS

The purpose of this dissertation research was to diagnose and propose a new way of approaching an existing problem concerning the development of functional requirements for NASA-Goddard's Command Management System (CMS) software design. At NASA-Goddard, the role of the CMS is to transform general requests for spacecraft operations into minutely detailed operational plans, including spacecraft commands with specific command execution conditions. The CMS is part of the NASA Data System, which entails the downlink of science and engineering data from NASA near-earth satellites to the user and the uplink of command and control data to the spacecraft.; It presently takes one to three years, with meetings once or twice a week, to determine functional requirements for CMS software design. As an alternative approach to the present method of developing CMS software functional requirements, an expert system prototype was developed in this dissertation research. Specifically, the knowledge base was formulated through interactions with domain experts and was then linked with an existing expert system application generator called KES.; Knowledge-base development focused on four major steps: (1) developing the problem-oriented attribute hierarchy; (2) determining the knowledge management approach; (3) encoding the knowledge base; (4) validating, testing, certifying, and evaluating the knowledge base and the expert system prototype as a whole.; An evaluation process was employed to assess the effectiveness of using the prototype over that of the status quo for CMS software functional requirements determination. Implementation of the prototype and knowledge refinement issues were also discussed.