具有一般工期与返工的耦合设计任务评审策略分析

A Analysis of reviewing strategies for coupled design tasks with general activity durations and rework

为了有效评价具有一般工期与随机返工的耦合设计任务评审策略,基于相型分布和连续时间马尔可夫链构建了项目完工时间概率分布估算解析模型。分析了两种基于平方变异系数的一般分布近似方法,选择其中一种更高效的方法对任务常规工期和返工工期进行近似,将任务执行相位视为虚拟任务进行项目网络转换;利用连续时间马尔可夫链描述转换网络的执行状态转移过程,并利用相型分布计算项目完工时间概率分布。以一类典型模具设计项目为例进行计算实验,分析多种项目环境参数对评审策略表现的影响,并通过模具设计项目案例分析验证了模型和方法的有效性。

To effectively evaluate the reviewing strategies for coupled design tasks with general activity durations and random rework,an analytical model for estimating the probability distribution of project completion time was constructed based on the phase-type distribution and continuous-time Markov chain.After analyzing two general distribution approximation methods based on squared?coefficient of variation,a more efficient method was selected to approximate the normal and rework activity duration.The project network was transformed by regarding each phase as a virtual task and the state transitions of the transformed network were described by a continuous-time Markov chain.The probability distribution of project completion time was finally obtained based on the phase-type distribution.Computational experiments were carried out taking a typical mold design project as an example,in which the influence of the project environmental parameters on the performance of reviewing strategy was analyzed.The proposed model and method were also verified by case study of mold design project.