Most organization-oriented methodologies for the analysis and design of multi-agent systems start defining the organization structure. This structure is defined in terms of roles that the agents have to play in the organization. However, there are cases where the identification of roles and protocols is not easy, so it is not convenient to start the analysis defining the organization structure of the multi-agent systems. In this work, we discuss the use of the organizational concept of business process to identify roles and protocols. Then, we present an approach, which is based on the business process concept, to extend the Gaia methodology. This approach defines how to derive the roles and protocols of a system from the business processes. This approach is described following a real case.