Early in the system design process, a design method must be chosen. This choice is usually dictated by what methods the designer has previously used, not by an open selection process. We provide descriptions of some available design methods and examples of their use. We develop benchmark problems that are solved by a variety of design methods and which identify characteristics of problems that might make one system design method more or less appropriate. The question we wish to answer is, "For which type of problem is each method best?" If a system is to be built, then that system must ultimately be described as a collection of state machines. However, these state machines are often not created by the systems engineers. The systems engineers use some method to create a high-level abstraction of the desired system. Then they turn this abstraction over to the specialty engineers who actually reduce it to a collection of state machines. We present solutions for a simple design problem by using the following 11 high-level system design methods: state transition diagrams, algorithmic state machine (ASM) notation, model-based system engineering, graphical description language, RDD-100, structured analysis, functional decomposition, object-oriented analysis (OOA) with Shlaer-Mellor notation, OOA and object-oriented design (OOD) with Booch notation, an operational evaluation modeling-directed graph, and IDEF0. Each method was used by an expert user of that method. The solutions presented make it obvious that the choice of a design method greatly effects the resulting system design.

It is argued that problems in the development of large computer-based systems indicate that a new discipline is needed at the systems engineering level. Designing systems with distributed processing and databases requires analysis of critical end-to-end processing flows to determine feasibility and proper allocation. An expanded skills base would be required to perform either systems, software, or hardware engineers to perform the necessary tradeoff studies. This paper informs managers, engineers, educators, and researchers about the need for computer-based systems engineering and the strategic opportunities this discipline provides for systems engineering improvement.>

The requirements driven design (RDD) languages, methods, and tools were developed to address the problems of defining and designing operational systems. The authors present the application of the RDD concepts to manufacturing system design, emphasizing the concerns of rapid prototyping/simulation.>

The Software Requirements Engineering Methodology (SREM) was presented to the Software Engineering community two years ago at the Second International Software Engineering Conference [1]; the SREM support software, the Requirements Engineering and Validation System (REVS), was also presented then [2]. SREM was developed for the Ballistic Missile Defense Advanced Technology Center (BMDATC) to address the generation and validation of software requirements for Ballistic Missile Defense Weapons Systems -- the motivation and environment for this research has been previously described [3]. At that time, REVS was operational only on the Texas Instruments Advanced Scientific Computer (TI ASC), and the methodology had been applied to one moderate sized "proof of principle" demonstration problem.

This paper describes an approach that can introduce some of the concepts of software engineering to general business, engineering, and science students in an introductory FORTRAN programming course. The approach integrates the notions of top-down design, stepwise refinement, structured flowcharting, test case description, and analysis in the context of a methodology for systematically developing and documenting programs. Qualitative results from teaching these concepts are presented.

This paper describes a methodology for the generation of software requirements for large, real-time unmanned weapons systems. It describes what needs to be done, how to evaluate the intermediate products, and how to use automated aids to improve the quality of the product. An example is provided to illustrate the methodology steps and their products and the benefits. The results of some experimental applications are summarized.