Change impact analysis of indirect goal relations: Comparison of NFR and TROPOS approaches based on industrial case study

Along with recent trends in using goal-oriented approaches for requirements engineering and system development activities, various techniques for managing adaptable stakeholder goals and requirements are proposed and used by the software engineering industry. Enterprise Architecture (EA) models which tie business goals, business processes and supporting IT systems are also expected to support reasoning on impact of changes on goals and requirements. Unfortunately common Enterprise Architecture (EA) frameworks like The Open Group Architecture Framework (TOGAF) and EA modeling languages like Archimate lacks support for analyzing goal and requirement change impacts in EA goal models. This paper reports an effort to fill this gap by extending a metamodel of already existing requirements and goal modeling language. The extension adds semantically reach definitions for goal influence relations that support reasoning on these relations. To leverage existing change impact analysis techniques, a literature review was conducted on existing goal change management techniques. Two candidate approaches (TROPOS and NFR framework) were chosen from the review results based on comparative analysis study. However, there is no evidence suggesting which of these two approaches suits more for EA goal model analysis. To find empirical evidence on the applicability of these approaches, we develop an adapted algorithm as well as a tool support for both techniques and apply both approaches on an industrial case study. Two main lessons were learned from the result of the case study. First both approaches have some limitations when applied to EA goal analysis and second, the NFR/Fuzzy logic based approaches provide more concrete results than the TROPOS based approaches.