With Aspect-Oriented Programming (AOP) a new type of system units is introduced (aspects). One observed characteristic of AOP is that it results in a large number of additional (coarse-grained to finegrained) system units (aspects) ready to be composed to the final application. With this growing number of system units the dependencies between them become vast and tangling. This results in the necessity of an improved management of the dependencies between these system units. Our paper investigates this problem, proposes a more general model (version model) to capture different facettes of AOP as well as a partial solution towards unit consistency based on versions.