Scheduling dynamic block assembly in shipbuilding through hybrid simulation and spatial optimisation

Abstract

Scheduling block assembly in shipyard production poses great difficulties regarding the accurate prediction of the required spatial resource and effective production control for achieving managerial objectives due to the dynamic spatial layout and the stochastic nature of the production system. In this study, this dynamic space-constrained problem is viewed as two sequential decisions, namely rule-based dispatching and a static spatial configuration. A novel hybrid planning method is developed to employ discrete-event simulation as look-ahead scheduling to evaluate the system performance under various control policies. To rationalise block placement and improve long-term area utilisation, a discrete spatial optimisation problem is formulated and solved using an enumeration-based search algorithm, followed by the application of a series of heuristic positioning strategies. By imitation of the dynamic dispatching and spatial operation, a statistical analysis of the resultant performance can be conducted to select the best-performing priority rules. A case study with an experimental investigation is performed for a local shipyard to demonstrate the applicability of the proposed method.