Scenario-based modifiability evaluation of service-based systems : tool support for lightweight scenario templates

Abstract

In modern software development, modifiability has arguably become one of the most important software quality attributes. There has been extensive research on the topic of the evaluation of a system's or architecture's ability to be modified. Scenario-based methods such as ALMA or SAAM have been around for a long time, and have proven to be effective ways to evaluate software. However, these methods are usually quite expensive in terms of time and require a big part of a project's stakeholders to align. One thing there has been a notable lack of is the modifiability evaluation specifically of systems using a service-based architecture. Properties of this architectural style can be useful to make more efficient assessments of a software's modifiability. This work seeks to propose a method to evaluate modifiability of service-based systems using a scenario-based analysis approach. Special emphasis is placed on this method being lightweight, i.e. less time-consuming and more flexible than similar methods. To achieve this, existing works on the topics of scenario-based software evaluation and the evolution of service-based systems were studied. Based on the acquired knowledge, a model of software change and an approach to analyze a system’s modifiability utilizing this model was designed. A tool was created to support our proposed method. Testing and applying the tool leads to iterative adjustments to the method. To demonstrate the insights that can be won using this method as well as how it is used, we perform an example application of it. The result of this work is a method that exchanges some of the reliability and accuracy of other scenario-based methods for flexibility and brevity. While the method achieves its goal of being lightweight, real-world testing and validation may lead to improvements to it.