One of the fundamental issues in Aspect-Oriented approaches is aspect-to-aspect interference, which occurs when multiple aspects are deployed jointly such that different composition orders may give rise to various inconsistency problems. This paper describes how aspect precedence can be specified explicitly at the modeling level in order to derive a correct composition order and therefore reduce the aspect interference problem in Aspect-Oriented Modeling (AOM). The paper presents a modeling approach to achieve aspect reuse by introducing three distinct categories of aspect composition mechanisms. These composition concepts have been implemented in the Motorola WEAVR, which is an AOM weaver developed at Motorola as a plug-in component for Telelogic TAU G2.