This paper studies the scheduling problem of storing and retrieving assembly blocks in a temporary storage yard.The objective is to minimize the number of relocations of blocks while the constraints for storage and retrieval time windows are satisfied. We present an integer programming model based on multi-commodity network flows, and the three revised models based on the properties of the problem. We show that the revised models are more efficient than the generic model through the numerical experiments.

This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License(http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. This paper deal with the block storage planning problem of storing and retrieving assembly blocks in a temporary storage yard with limited capacity, which is one of the critical managerial problems in shipbuilding. The block storage planning problem is required to minimize the number of relocations of blocks while the constraints for storage and retrieval time windows are satisfied. We first show NP-hardness of the block storage planning problem. Next we propose a heuristic algorithm to generate good quality solutions for larger instances in very short computational time. The proposed heuristic algorithm was validated by comparing the results with the mathematical model presented in the previous study.

We deal with the design of the effective block logistics operating system in shipyard. The block logistics operation is one of the critical managerial problems in shipbuilding. The block logistics operation in shipyard consists of storage operation for temporary storage in the limited storage area and transfer equipment operation of blocks from the given storage area to next process according to the block production schedule. We propose a design method of block logistics operating system based on the axiomatic design and IDEF0 method. As a result of axiomatic design, system functions are determined regarding implementation sequence. We validated the proposed design by implementation of a block logistics operating system for a large scale shipyard.