A TABU SEARCH ALGORITHM FOR A PIPE-PROCESSING FLOWSHOP SCHEDULING PROBLEM MINIMIZING TOTAL TARDINESS IN A SHIPYARD

This paper focuses on scheduling problem of a pipe-processing flowshop in a shipyard. The flowshop composes of five stages, including cutting, bending, welding preprocessing, argon-welding and CO2-welding, and each stage consists of identical parallel machines. Since thousands of pipes are mounted on the hull block before erection, the pipe-processing scheduling is a critical task for shipbuilding to meet the due date of the block erection. A tabu search algorithm is developed for the scheduling problem with the objective of minimizing total tardiness. Computational experiments are performed on the collected real data. Results show that the proposed algorithm is efficient for this problem.