The increasing complexity and dynamics in which software systems are deployed call for solutions to make such systems autonomic, i.e., capable of dynamically self-adapting their behavior in response to changing situations. To this end, proper models and software engineering tools are required to be available to support the design and development of autonomic systems. In this paper, we introduce a new general model, SOTA, for modeling the adaptation requirements. SOTA, by bringing together the lessons of goal-oriented modeling and of context-aware system modeling, has the potentials for tackling some key issues in the design and development of complex self-adaptive software systems. In particular, SOTA enables: early verification of requirements, identification of knowledge requirements for self-adaptation, and identification of the most suitable self-adaptive patterns.