In dynamic e-business, organizations collaborate in a just-in-time fashion using loosely coupled services. To ensure interoperability of the services, behavioral mismatches between their protocols need to be resolved in a fast and efficient way, which can be done with protocol adaptors. We present an efficient, automated method to construct (if possible) a minimal protocol adaptor with parallelism for two asynchronously communicating business protocols. A minimal adaptor only processes those messages that cause the mismatch, and has less message overhead at run-time than a non-minimal adaptor. Existing methods only build adaptors that are sequential, synchronous, or non-minimal. We show that the proposed method increases the efficiency of s...