The Uniied Modeling Language and Performance Engineering 2 past Work in Software Performance Engineering 2.2 past Approaches 2 -extending Formal Notations

The use of performance analysis and prediction techniques by software designers and software engineers is at best inconsistent and at worst simply does not happen. This is principally because these techniques are seen as separate and diicult to apply. Work on Software Performance Engineering, initiated by Smith, has sought to bridge the gap, but has had limited success. With the emergence of a widely accepted standard for software design { the Uniied Modeling Language { the time seems ripe for an attempt to integrate performance directly into this process, by exploiting the notation directly. This paper reviews past work in Software Performance Engineering, summarizes the Uniied Modeling Language and presents encouraging result from merging these two techniques. 1 Motivation To encourage designers to incorporate performance analysis, work such as that by Smith on Software Performance Engineering 25] and by Beilner and others on HITT4] has built new performance evaluation frameworks aimed at designers. At the same time others have added performance annotations to existing design notations and provided routes for analyzing the resulting models. Most success is likely to come from those projects which attempt to build performance analysis directly into accepted design methods. The integration of performance estimation with the system design process is the goal of the work described in this paper. The emergence of a widely accepted new standard for object oriented software design, known as the Uniied Modeling Language (UML) 23, 28] has made it possible to focus on a single notation. Since that notation includes both static and dynamic aspects of systems it is very well suited to generating performance results, although additional information on timings and branching probabilities is needed. Here we consider some examples of using UML for performance prediction. The rest of this paper is structured as follows. In section 1 previous work in performance engineering is reviewed Section 2 outlines the UML itself, concentrating mostly on the dynamic modelling aspects of the language. Section 3 considers how to exploit the UML for performance analysis. This includes examples of direct use of UML within Section 4 considers where this work might lead and the beneets that might follow if it is successful. Connie Smith 25] rst used the term \performance engineering" to describe the application of performance evaluation techniques to software systems. She presented the case for an approach which brought performance evaluation and design together. For non-specialists, the eld of performance …