Research that considers the long-term maintenance impact of using COTS components (Carney 2000, Dean 1999) is also being investigated. This paper is organized as follows. Following the introduction, we present the CARE approach and illustrate its use with an example. These are followed by a section for the conclusions and future work. THE CARE APPROACH The CARE approach draws upon the good ideas available in current RE methodologies including RUP, MBASE and ACRE/PORE. The aim is to complement and extend these methodologies. The scope of the process model described here is restricted to the requirements phase of the software development lifecycle. The description does not, for example, consider the design, implementation, testing, and maintenance phases. The CARE approach is being developed using a set of examples for a Digital Library System (Chung 2001a, Chung 2001b). In this description of the model, the customer is contracting the development of a large scale system and is involved in the development work. Variations of this model can be developed in the future to consider high volume, shrink-wrap product development. Overview. The CARE approach is characterized as goal-oriented, agent oriented, knowledge based, and has a defined methodology, or process (refer to Figure 1). When the development of a system begins, the stakeholders' goals for the system under development Component Repository (Foreign Goals, Foreign Requirements)
are defined first. Our CARE approach is softgoaloriented for the purpose of tradeoff analysis. For this, the nonfunctional requirement (NFR) framework (Chung 2000, Mylopolous 1992) is used which allows for a systematic approach to dealing with nonfunctional requirements. Using the NFR Framework, functional alternatives can be explored and represented through OR-dependencies. Once defined, the goals are used to drive the development of the system. First, the goals are refined into system requirements. In turn, system requirements may be refined into software, hardware, or interface requirements. Currently, the latter refinement step is not considered in the CARE approach. The CARE approach is agent oriented. The agents are the stakeholders for the system under development. An agent is intentional and possesses intentional properties including goals, beliefs, abilities, and commitments. An agent is also autonomous and makes decisions, choices, and depends on other agents to accomplish goals, complete tasks, or furnish resources. An agent can analyze its opportunities and risks in the various proposals and configurations for a system. The notation used to support this aspect of the CARE approach is drawn from the i* framework (Yu 1994), which describes goal and softgoal dependencies among agents and how they accomplish a goal in terms of subgoals, softgoals, and tasks. These concepts are embedded into the conceptual modeling language Telos (Mylopolous 1990), a descendent of RML (Greenspan 1994)- an object oriented requirements modeling language for functional requirements. As a result, i* System Under Development (Native Goals, Native Requirements)

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