In this paper, we present a new approach for business processes integration. Our approach is based on interaction protocols that enable autonomous, distributed business process modules to integrate and collaborate. In our case, the business processes integration is modelled using AUML and specified using BPEL4WS. Furthermore and to increase the reliability of interaction protocols at design time, our approach presented in this paper can validate the BPEL4WS specification with business constraints (specified by means of OCL). The validated BPEL4WS specification is considered as a specification language for expressing the interaction protocols of the multi-agents system, which can then intelligently adapt to changing environmental conditions.