The evolution in information technology has allowed the development of new DSS architectures. This paper presents a framework for developing a web-based optimization decision support system for intra/inter-organizational decision-making processes. Data exchange in inter-organizational decision, separate decision and data models, and web services technology have been raised. Considering these factors a framework for developing a DSS with web services have been defined. In a business context, these web services could be offered for different web services provider companies and used by the different participants in an intra/inter-organizational decision-making process. In order to contextualize this framework, three scenarios have been defined and different relationships have been identified between the participating enterprises.