UN/CEFACT’s Modeling Methodology (UMM) has been developed to analyze and design B2B business processes independent of the underlying exchange technology. It became the methodology of choice for developing ebXML business processes. Another technology for realizing B2B partnerships is Web Services. Currently, the business process execution languages (BPEL) seems to be the winner amongst the Web Services languages for orchestration and choreography. If Web Services is used as underlying exchange technology for B2B, the semantics of UMM business processes must be represented in BPEL. The goal of this paper is to verify whether BPEL is appropriate to capture UMM business collaborations or not. For this purpose we describe a transformation from UMM to BPEL.