CONCURRENT ENGINEERING: Research and Applications A Constraint-driven Execution Plan for Maximizing Concurrency in Product Development

Abstract: One of the major goals of Concurrent Product Development (CPD) is to shorten the design cycle time by increasing more task overlaps of the ensuing design activities. Increasing task or activity overlap often hinges on two timing questions (a) ‘‘When does the downstream activity require certain information from its upstream activities and (b) when will the required information on an activity be available for scheduling the next dependent task?’ ’ The paper discusses a constraint-driven execution plan to handle the concurrency during scheduling of various dependent tasks. This constraint-driven execution plan is designed to relieve the alignments of start and end points commonly encountered during scheduling of the concurrent tasks. It is not essential that an activity will start only when a dependent activity is fully finished. In constraint-driven execution plan, a task or an activity can be initiated as soon as the required information is available rather than after the completion of all the upstream activities dependent on it. The paper shows that if we follow this execution plan during a CPD process, concurrencies among the ensuing design activities can be maximized. The paper also discusses how this execution plan can be used in a context of a workflow management system (WfMS). Employing this plan, it is possible to easily transform most of the event-condition-action (ECA) rules-based workflow model – from its activity completion event-driven forms – into an information-constraint-satisfaction-driven forms. This execution plan, thus, enables an event-driven WfMs to support concurrency of tasks during product development and concurrent tasks’ scheduling