A generalized environment for evaluation and optimization of complex, large scale systems design

Large-scale, complex systems can be much better designed or greatly improved through re-architecture of overall system, subsystems, and components. However, the number and variety of components and their interfaces make finding optimal system designs very difficult because existing tools tend to be domain or method specific, and no one tool is sufficient to deal with the diversity of components in a complex system which spans multiple domains. What is needed is a methodology which progressively breaks down the complex design evaluation and optimization problem into smaller sub-problems. For each of these sub-problems, an appropriate domain or method specialized tool should be used. Hence, there is a need for a control mechanism which supervises and coordinates the use of diverse specialized tools and enables component by component, systematic design evaluation and optimization of a complex system. We describe an environment which includes such a control mechanism, here referred to as Master-front-end. The environment is domain-independent and applicable across a wide variety of complex systems design. The feasibility and usefulness of the environment has been illustrated by applying it in an example system--a distributed, complex, information system for military command and control. In Chapter 1 of this dissertation, we describe the problem of large scale, complex system design evaluation and optimization. Chapter 2 describes the current state of the art and the need for innovations to solve the problem. Chapter 3 describes a divide-and-conquer methodology to handle system complexity. In this methodology a complex system is divided hierarchically into levels of components. Also a hierarchy of metrics, called System Design Factors (SDF), defines diverse evaluation methods. The Master-front-end oversees the level by level evaluation and optimization. Chapter 4 describes the architecture of the environment which includes the Master-front-end. The Master-front-end controls an open-ended architecture connecting existing commercial and R & D automated specialized system evaluation tools. Chapter 5 gives illustration of the environment operation by applying it in the example military command and control centers information system design. Chapter 6 details the environment technology including use of modern database, communication, and graphics technology. Because of the divide-and-conquer, data management can be based on simple flat files. The human engineered Graphical User Interface is based on Java applets. The user is able to visualize, modify and submit evaluations to the specialized tools. Chapter 7 concludes the dissertation giving an overview of the results of this research