This paper proposes a scheduling system for pipe processing in shipyards to improve productivity. The pipe processing consists of five stages, including cutting, bending, welding preprocessing, argon welding, and CO2 welding. First, the bottleneck stage is selected, and then the longest time processing first (LPT) algorithm is applied to construct the schedules of the bottleneck and the upstream stages. For the downstream stages, the local bottleneck among these stages is selected, and the above scheduling procedure is performed again to construct schedules for the stages ahead of the local bottleneck stage. The scheduling algorithm is applied again and again, until the schedules for all stages have been constructed. Finally, the test is performed on the real data, and the experimental results demonstrate that the proposed algorithm can efficiently improve the productivity of the pipe-processing flowshop.