The effects of intermittent work patterns and funding on the costs of U.S. Navy ship repair and maintenance were modeled for the San Diego region in 2002 for Supervisor of Shipbuilding and Repair (SUPSHIP) San Diego. One of the private shipyards that participated in the study requested that CACI adapt the aggregated regional model to a more specific, proprietary model. The goal was to use insights gained from the model to better understand and control cost. This paper reports on the development of the private shipyard workflow model. The model allows the shipyard to experiment with different patterns of work, availability schedules, hours, repair availability length and start dates to determine the overall loading of the shipyard's 17 trades over one or more fiscal years. It incorporates human resources, scheduling, financial, infrastructure and work sectors. Important factors considered in the model are volume, productivity, experience, manday rate and error rate. A shipyard's manday rate is the nominal, fully burdened cost of one shipyard worker for one day at straight time. The model estimates work to be scheduled, actual work accomplished, workforce used and the cost to the government.