混合工作日历下资金受限工程项目工期最短化任务指派方法

针对一类混合工作日历下资金受限工程项目工期最短化任务指派问题,提出了一种基于遗传算法的优化方法。对混合工作日历下资金受限工程项目工期最短化任务指派问题进行了描述,并设计了遗传算法对问题进行求解。提出了基于承包商工作日历的时间推算机制,设计了时间推算函数作为混合工作日历下工程项目工期推算的基础;算法采用"基于承包商号的整数编码方式"对个体进行编码和"拒绝策略"产生初始可行种群,使用"交叉算子改进策略"和"两点交叉方式"进行交叉以保证交叉后子个体可行,采用"拒绝策略"和"单点变异方式"进行变异以保证变异后子个体可行,解码过程中基于"关键路径法"和"正向推算函数FC"推算项目工期。通过案例分析验证了所提方法的有效性。

Task assignment optimization method of getting shortest project duration for engineering project with capital limit under mixed work calendars

This paper presents an optimization method using a genetic algorithm to solve the task assignment problem of achieving the shortest project duration for an engineering project with capital limit under mixed work calendars. Firstly, the problem was described. Then, a genetic algorithm was designed to solve the researched problem. A time reckoning mechanism based on the contractor''s work calendar was proposed and related time reckoning functions were designed as the basis of calculating project duration for an engineering project under mixed work calendars. An integer coding method based on contract number was used to encode the chromosome. The refusal strategy was used in the population initialization to ensure the feasibility of chromosomes. To ensure the feasibility of offspring chromosomes, an improved crossover operator was used in the crossover operation based on the two-point crossover method, and a refusal strategy was used in the mutation operation based on the single-point mutation method. Finally based on the critical path method, the forward reckoning function FC was used to get the shortest project duration. The effectiveness of the proposed method was verified by a case study.