Using Model Transformation Language Semantics for Aspects Composition

Modern software systems are huge, complex, and greatly distributed. In order to design and model such systems, software architects are faced with the problem of cross-cutting concerns much earlier in the development process. At this level, cross-cutting concerns result in model elements that cross-cut the structural and behavioral views of the system. Research has shown that Aspect Oriented (AO) techniques can be applied to software design models. This can greatly help software architects and developers to isolate, reason, express, conceptualize, and work with cross-cutting concerns separately from the core functionality (Ajila et al., 2010; Petriu et al, 2007). This application of AO techniques much earlier in the development process has spawned a new field of study called AspectOriented Modeling (AOM). In AOM, the aspect that encapsulates the cross-cutting behavior or structure is a model, just like the base system model it cross-cuts. A system been modeled has several views including structural and behavioral views. Therefore, a definition of an aspect depends on the view of interest. Unified Modeling Language (UML) provides different diagrams to describe the different views. Class, Object, Composite Structure, Component, Package, and Deployment diagrams can be used to represent the structural view of a system or aspect. On the other hand, Activity, State Machine, and Interaction diagrams are used to model the behavioral view. Interaction diagrams include Sequence, Interaction Overview, Communication, and Timing diagrams.