A method for man hour optimisation and workforce allocation problem with discrete and non-numerical constraints in large-scale one-of-a-kind production
针对单件大规模生产（如船舶建造）中复杂的工时优化问题，提出一种自上而下的细化方法，将产品设计与生产分解为三种基本任务结构，并采用矩阵实数编码遗传算法和动态规划求解，案例验证了提升生产效率的潜力。
In one-of-a-kind production (OKP), how to coordinate workforce allocations to obtain reasonable man-hour has the practical significance. However, plenty of variables and complicated operation relationships are involved, which implies the man-hour optimisation in OKP belongs to a constrained mixed discrete optimisation problem. In this article, to deal with the man-hour optimisation in large-scale OKP which often refers to complex production, e.g. shipbuilding, we introduce a top-down refinement method to specialise the product design and production decomposition in OKP, which also indicates the operation relationships of the interim product production processes. Consequently, we suggest three basic task structures which are with wide adaptability in OKP industry: tandem structure, parallel structure and double-level-nested parallel structure. Meanwhile, for the double-level-nested parallel structure, a method based on matrix real-coded genetic algorithm and dynamic programming is presented to solve the man-hour optimisation and labour force allocation problem. Through the case studies, including an industrial implementation in the shipbuilding interim product (i.e. a hull block) production, our optimisation method demonstrates significant potential to improve the production efficiency.