A Lightweight GRL Profile for i* Modeling

The i* framework is a popular conceptual modeling language for capturing and analyzing socio-technical motivation and properties of complex systems in terms of actors, their intentions, and their relationships. In November 2008, the International Telecommunications Union finalized the standardization of the User Requirements Notation (URN). URN is composed of two loosely coupled yet integrated sub-languages: the Goal-oriented Requirement Language (GRL), which is an intentional modeling language based on a subset of i*, and the Use Case Map notation for representing and capturing high-level system scenarios and structures. GRL was specifically defined in a non-restrictive way to foster the development and use of different agent and/or goal modeling approaches and techniques. However, because of its permissiveness, GRL can be used in ways that deviate from conventional i* modeling guidelines. In addition, some i* concepts do not have equivalent first-class concepts in GRL. In this paper, we present a lightweight GRL profile for i* that takes advantage of GRL’s extensibility features to capture missing i* concepts. The profile presents formal constraints on the use of GRL and its extensions to restrict it to an i* style. Using GRL constrained by this profile enables GRL modeling and analysis tools to be used for i* models, and ensures that resulting i* models conform to an international standard and that they can be integrated with Use Case Maps. Variants and extensions of the original i* can also be supported in a similar way. This profile is implemented in the jUCMNav modeling tool.