Owing to the dynamicity of business environments in which organizations must quickly adapt to changes, the information systems have recently had to adapt to new situations so that they can keep adding value efficiently and effectively. In the light of this scenario, a new discipline called Service-oriented Systems Engineering has emerged in the academic scene and this has highlighted the disciplined, systematic and quantified development of Service-oriented Computing systems. This discipline is divided into other subdisciplines; one of these sub-disciplines is Service-oriented Requirements Engineering (SORE) and it is concerned with defining processes and methodologies to address the question of services requirements from two different perspectives: service consumer and service provider. In the SORE context, this paper proposes the WS&i*-RGPS approach that explores some alternatives to the descriptions proposed by the Role, Goal, Process and Service (RGPS) metamodels -an approach in SORE. This involves a new definition that seeks to incorporate the benefits of other methodologies -established in the literature -with RGPS. Accordingly, this new approach outlines the use of the i* Framework to describe the Role and Goal layers and shows the use of WS-BPEL/WSDL to describe the process and service layers. The use of the i* Framework sets out the goals for managing different aspects of the systems specification. Moreover, this paper presents a comparison among WS&i*-RGPS and other SORE approaches based in three parameters presented in SORE literature.