Abstract
Engineering design activities in distributed environments like the Web require fault tolerance and concurrent access to shared resources such as databases and Web servers. Such activities are generally dynamic, cooperative, long-lived, interactive and non-prescriptive. We propose a new multi-agent transaction model, which is based on extended transactions and multi-agent technologies. The novelty of this model is that it automatically customises transactions to the requirements of design activities. In addition, this model is believed to improve concurrency, fault tolerance, facilitate interaction between and co-operation among the participating systems involved in design activities. The proposed model is formally specified using CCS (Calculus of Communicating Systems) language. Formalisation is crucial in ensuring the correctness, reliability, and recovery of multi-agents transactions, given the complex and unreliable nature of the distributed design activities.