Modern information systems, which are the result of the interconnection of systems of many organizations, run in variable contexts, and require both a lightweight approach to interoperability and the capability to actively react to changing requirements and failures. Model-Driven Development (MDD) and Service-Oriented Architecture (SOA) are software development approaches that deal with this complexity, reducing time and cost development and augmenting flexibility and interoperability. Although, requirements engineering is accepted as a critical activity in these approaches, there is a need to appropriately integrate and automate the requirements modeling and transformation tasks as part of MDD and SOA development approaches. Our proposal is a Rational Unified Process (RUP) extension, in which the requirements discipline is placed in a model-driven context in order to derive SOAs. This paper includes the definition of a model-driven requirements process including activities, roles, and work products.