On the Reuse of Goal Models

Abstract

The reuse of goal models has received only limited attention in the goal modeling community and is mostly related to the use of goal catalogues, which may be imported into the goal model of an application under development. Two important factors need to be considered when reusing goal models. First, a key purpose of a goal model is its evaluation for trade-off analysis, which is often based on propagating the contributions of low-level tasks (representing considered solutions) to high-level goals as specified in the goal model. Second, goal models are rarely used in isolation, but are combined with other models that impose additional constraints on goal model elements, in particular on tasks. For example, workflow models describe causal relationships of tasks in goal models. Similarly, feature models describe further constraints on tasks, in terms of which tasks may be selected at the same time. This paper (i) argues that reusable goal models must be specified either with real-life measurements (if available) or with relative contributions, (ii) presents a novel evaluation mechanism that enables the reuse of goal models with relative contributions, while taking into account additional constraints on tasks in the goal model expressed with feature models, and (iii) discusses a proof-of-concept implementation of the novel evaluation mechanism.