1. A system for simulating distributed product development comprising a plurality of discrete projects which are developed at a plurality of development sites, the system comprising: a plurality of site-specific discrete event product development simulation models configured to model development at the plurality of development sites by operating on site-specific product development data to produce simulation metrics for the plurality of development sites, wherein each of the plurality of development sites is associated with a corresponding site-specific discrete event product development simulation model of the plurality of site-specific discrete event product development simulation models, and wherein each site-specific discrete event product development simulation model models actual development processes occurring at its associated development site; and a plurality of system dynamics simulation models, the system dynamics models configured to operate on product development data and simulation metrics to produce simulation metrics, the plurality of system dynamics simulation models comprising: a plurality of site-specific system dynamics models configured to interact with the site-specific discrete event product development simulation models, receive data and metrics, and produce simulation metrics for the plurality of development sites, wherein each of the plurality of development sites is associated with a corresponding site-specific system dynamics model of the plurality of site-specific system dynamics models; and one global system dynamics simulation model configured to interact with the plurality of site-specific system dynamics models, receive data and metrics, and product global product development simulation metrics.