The Aspect-oriented User Requirements Notation (AoURN) is a framework that combines goal-oriented, scenario-based, and aspect-oriented modeling in support of requirements engineering activities.

AoURN extends the User Requirements Notation (URN) with aspect-oriented concepts, allowing modelers to better encapsulate crosscutting concerns which are hard or impossible to encapsulate with URN models alone. AoURN adds aspect concepts to URN’s sub-languages, leading to and integrating Aspect-oriented GRL (AoGRL) and Aspect-oriented UCMs (AoUCM). The three major aspect-oriented concepts that have to be added to URN are concerns, composition rules, and pointcut expressions. Note that the term aspect refers to a crosscutting concern, while the term concern encompasses both crosscutting and non-crosscutting concerns. These are core concepts of many aspect-oriented modeling (AOM) techniques. In terms of aspect-oriented programming (AOP), the concept of a crosscutting concern in AOM relates to the concept of an aspect and the aspect’s advice in AOP, the concept of composition rules in AOM encompasses the common before/after/around operators in AOP, and the concept of pointcut expressions is the same in AOM and AOP.

A concern is a new unit of encapsulation that captures everything related to a particular idea, feature, quality, etc. AoURN treats concerns as first-class modeling elements, regardless of whether they are crosscutting or not. Typical concerns in the context of URN are stakeholders’ intentions, NFRs, and use cases. AoURN groups all relevant properties of a concern such as goals, behavior, and structure, as well as pointcut expressions needed to apply new goal and scenario elements to a URN model or to modify existing elements in the URN model.

Pointcut expressions are patterns that are specified by an aspect and matched in the URN model (often referred to as the base model). If a match is found, the aspect is applied at the matched location in the base model. The composition rule defines how an aspect transforms the matched location. AoURN uses standard URN diagrams to describe pointcut expressions and composition rules (therefore AoURN is only limited by the expressive power of URN itself as opposed to a particular composition language). AoURN’s aspect composition technique can fully transform URN models.

Finally, aspects may depend on or conflict with each other. AoURN models dependencies and conflicts among concerns and the resolution thereof with the help of the concern interaction graph (CIG). Many aspect interactions can be resolved with precedence rules. The CIG is a specialized GRL goal graph that uses dependencies, correlations, and intentional elements to model such precedence rules. The precedence rules then govern the order in which concerns are applied to a URN model.

The following papers give a good first introduction to AoURN:

• Mussbacher, G. and Amyot, D. (2009) Extending the User Requirements Notation with Aspect-oriented Concepts. 14th SDL Forum (SDL 2009), Bochum, Germany, September 2009. Reed, R., Bilgic, A., Gotzhein, R. (Eds.), SDL 2009: Design for Motes and Mobiles, Springer, LNCS 5719:115–132
• Mussbacher, G., Amyot, D., Araújo, J., and Moreira, A. (2010) Requirements Modeling with the Aspect-oriented User Requirements Notation (AoURN): A Case Study. Katz, S., Mezini, M., and Kienzle, J. (Eds.), Transactions on Aspect-Oriented Software Development (TAOSD) VII, Springer, LNCS 6210:23–68.

For papers more specific to AoUCM, try

• Mussbacher, G., Amyot, D., and Weiss, M. (2007) Visualizing Early Aspects with Use Case Maps. Rashid, A. and Aksit, M. (Eds.), Transactions on Aspect-Oriented Software Development (TAOSD) III, Springer, LNCS 4620:105-143,
• Mussbacher, G., Amyot, D., and Whittle, J. (2009) Refactoring-Safe Modeling of Aspect-Oriented Scenarios. ACM/IEEE 12th International Conference on Model Driven Engineering Languages and Systems (MODELS 2009), Denver, USA, October 2009. Schürr, A. and Selic, B. (Eds.), Model Driven Engineering Languages and Systems, Springer, LNCS 5795:286-300, and
• Mussbacher, G., Amyot, D., Whittle, J., and Weiss, M. (2007) Flexible and Expressive Composition Rules with Aspect-oriented Use Case Maps (AoUCM). 10th International Workshop on Early Aspects (EA 2007), Vancouver, Canada, March 13, 2007. Moreira, A. and Grundy, J. (Eds.), Early Aspects: Current Challenges and Future Directions, Springer, LNCS 4765:19-38.

A complete listing of all papers related to AoURN is available as a search of the URN Virtual Library and on Gunter's publication page.

Tool support for the matching and composition of AoURN models is available starting with version 4.3 of jUCMNav. The following three demos explain

• how to create an aspect-oriented scenario model with AoURN, and

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• how to manage concerns and assign URN diagrams to a concern,

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• how to match/compose an aspect with an AoURN model (this can be undone/redone by going to the aspect map and clicking the undo/redo buttons).

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A list of all current test cases for AoURN including their up-to-date fail/success status is available on the AoURN Test Suite page.