Decision Support System for Shop Capacity Planning Across Multiple Shipyards
Culver, P., Welch, J., & Walden, C. (2007). Decision Support System for Shop Capacity Planning Across Multiple Shipyards. ShipTech 2007. Biloxi, MS: Naval Metalworking Center.
One means for the shipbuilding industry to improve performance is to more effectively use key resources, and to do so through better planning. However, given the industry’s complex operating environment, improved planning requires sophisticated modeling tools. This presentation discusses the design, development, and use of a decision support system (DSS) that is used by Northrop Grumman Ship Systems to enhance and facilitate capacity planning across multiple shipyards. This advanced planning system uses multiple types of models to plan and schedule the work associated with producing pipe details for multiple ship programs. The first model type considers pipe details at a high level and from a capacity planning perspective. Each detail is considered to be a resource-constrained project. Resource leveling strategies are used to make high-level production decisions based schedule, resource availability, and resource loadings on the bottleneck operation (fitting and welding) in each shipyard. The second type of model considers pipe details at a lower level and from an operations perspective. Other shop resources are modeled and the stochastic nature of the real system is considered. Discrete-event simulation is used to model the cutting, bending, fitting, and welding areas in each shipyard. The simulation models are used to assess a high level plan and to establish the capacity level that is used in the high-level model. The process times for each pipe detail are parametrically determined based on physical characteristics of the pipes, including material, size, number of purchased parts, etc. The two disparate types of models are linked through a DSS. The DSS also supplies the models with the data they require (product and process characteristics) and provides the user with the information they need to make timely and effective decisions. The system is designed to be used to support analyses involving both short- and long-term planning horizons.