Sharing Web services across the enterprise and to support B2B integration becomes more, intensive and critical for businesses. This paper proposes a process to generate Web services from the attributes describing the business objects and the coordination artefacts as described in the highest abstraction level of a business model i.e. the universe of discourse where the elements are unique. The process is based on a new concept we introduce and call factual dependency, Factual dependency is a mechanism used to aggregate attributes that are concerned by the same DB CRUD operations with respect to the time and the space. Factual dependencies are then validated with regard to the possible business events to keep only the relevant ones. Each distinct and valid factual dependency is specified in terms of input/output parameters to generate a lowest level of granularity Web services. These Web services are then registered to be discovered and (re)used at request by business processes in their reengineering or composition.