The Flow-Service-Quality Framework: Unified Engineering for Large-Scale, Adaptive Systems

Modern enterprises are irreversibly dependent on large-scale, adaptive, component-based information systems whose complexity frequently exceeds current engineering capabilities for intellectual control, resulting in persistent difficulties in system development, management, and evolution. We propose an innovative framework of engineering representation and reasoning methods for developing these complex systems: the FlowService-Quality (FSQ) Framework. In dynamic network information systems with constantly varying function and usage, work flows and their corresponding traces of system services act as stable foundations for functional and non-functional (quality attribute) specification, design, and operational control. Our objective is to provide theoretical foundations, language representations, and rigorous yet practical unified engineering methods to represent and reason about system flows as essential artifacts of system specification, design, and operation. 1. Intellectual Control in Large-Scale System Development Modern enterprises are irreversibly dependent on large-scale information systems whose complexity frequently exceeds current engineering capabilities for intellectual control, resulting in persistent difficulties in system development, management, and evolution. Critical enterprise missions depend on system services composed of complex combinations of distributed computation, communication, and human components whose interactions are often not fully understood. These 0-7695-1435-9/02 $ f the 35th Annual Hawaii International Conference on System Sciences (HICSS-35’02) 9/02 $17.00 © 2002 IEEE large-scale systems are characterized by powerful functionality that supports enterprise business models, extensive simultaneous operations by many users, massive integration of commercial off-the-shelf (COTS) components of uncertain reliability and quality, and often, inflexible designs that limit adaptability and evolution. At the same time, enterprises place extraordinary demands on systems for reliability, integrity, performance, scalability, and other key quality attributes [4]. Today’s network systems exhibit extensive asynchronous behavior in their virtually unknowable interleaving of communications among system components. In addition, system complexity is often compounded by indeterminate boundaries, everchanging couplings to other systems, and continual requirements for functional evolution. The development of these systems is essentially a large-scale integration activity that seeks to reconcile and satisfy user requirements through combinations of commercial off-the-shelf (COTS) components, often within a framework of pre-defined environments, enabling technologies, and domain architectures. The central issue in modern system development is how to maintain intellectual control over such complex structures and the asynchronous behaviors they produce. In short, what are the stable and dependable anchors for specification and design that can provide a unified engineering discipline for large-scale network system development? In this paper we propose a comprehensive and effective answer to this question. The Flow-ServiceQuality (FSQ) Framework is defined and discussed. Section two outlines the characteristics and behaviors of 17.00 (c) 2002 IEEE 1 Proceedings of the 35th Hawaii International Conference on System Sciences 2002