The idea of developing software systems by putting software modules together has been a goal for many software researchers and practitioners for a long time. This goal is within sight due to the increased adoption of component-based software engineering, the development of component standards, and their wide acceptance by industry. Component-based development is an approach to developing a software system by assembling and composing already built software components. It promises reusable and plug-and-playable software system development environments. The component concept is not new and has been perceived in several different ways by software researchers in academics and practitioners in industry. The different perspectives from diverse researchers and practitioners have led to a plethora of definitions of component and different component specification and implementation models. In this paper, we briefly review several of these different views and definitions on software components. We then present the Interoperable Component Specification Model (ICSM) for the Web services environment.

C. C. Shen and W. H. Tsai (IEEE Trans. Comput., vol.C-34, no.3, p.197-203 1985) proposed a graph matching algorithm for solving the static task assignment problem. It combines two important ideas: (1) graph homomorphism and (2) application of the A* algorithm. Task-dependent information is used as a heuristic to reduce the search effort in finding an optimal path to the goal node. An examination is made of Shen and Tsai's strategy and their complexity measure. The authors propose some simple alternatives to their algorithm that are effective in reducing the number of nodes generated (and expanded) without sacrificing the optimality criteria.>