Modeling approaches often are not adapted to human reasoning: models are ambiguous and imprecise. A same model element may have multiple meanings in different functional roles of a system. Existing modeling approaches do not relate explicitly these functional roles with model elements. A principle that can solve this problem is that model elements should be defined in a context. We believe that the explicit modeling of context is especially useful in Business Process Modeling (BPM) where the meaning of any model element should be defined precisely. The contribution of our work is at the contextaware modeling framework for BPM. We model a system as the composition of small roles, where each role of a system is defined in its own context.