A DSS for distributed computer system design in the presence of multiple conflicting objectives

摘要

The design of distributed computer systems (DCS) requires compromise among several desirable and conflicting objectives. Design tools for this purpose should, therefore, facilitate the process of making such tradeoffs. To this end, this paper presents a prototype Decision Support System (DSS) which uses multicriteria decisions making techniques as the underlying methodology to aid the designer in making compromises in a systematic and efficient manner.While there are several isolated subproblems of DCS design that can be modelled and solved quantitatively, there are also, many design aspects that are difficult to quantify and/or formalize. Thus the design process requires a synthesis of analytic model execution and informed judgement on the part of the designer. The DSS aids in this iterative process by executing appropriate models and generating a sequence of ‘Pareto-optimal’ or non-dominated set of solution vectors. The relatively unstructured task of making tradeoffs among the components of each vector is left in the hands of the designer. Efficiency is achieved by avoiding needles search through clearly inferior solutions and focusing on non-dominated ones only. Various details of the prototype, implemented on a UNIVAC 1100 and an IBM PC AT, are highlighted in an example session. The potential advantages of using multicriteria techniques as opposed to the widespread practice of using single criteria optimization methods are also noted in this paper.