Collaborative and distributed engineering web services are emerging as a viable alternative to the traditional design and engineering process automation. Existing approaches have limitations in supporting long-running engineering transactions, automatic engineering process orchestration and choreography, synchronous and asynchronous conversation, and geometric abstraction for transmission and sharing. In this paper, we present a process-centric engineering web service methodology to overcome these limitations by utilizing BPEL-based (Business Process Execution Language) process templates and coordination broker-based conversation support. This paper discusses the synchronization of engineering web services which can be either peer-centric or process-centric to support long-running engineering transactions and conversation. The process orchestration and choreography broker works as a service dispatching and aggregation mediator for executing process templates, which enables the individual activity or the engineering process to dynamically select and invoke one of the alternative web services through the run-time process brokering. Further, the paper presents how to support collaboration over the running process using conversation policy.