The Planning And Scheduling Model Of Multi-Objective Activity Network And Its Optimization Algorithm

The network plan based on activity is one of the most common ways which used in project management of the modern enterprises. An effective network plan is regarded as a good start of the project. With the development of global economy, enterprises are facing more and more fierce competition. The survival and development of the enterprises are directly related to the network planning. However, several problems of the existing network planning model appears: First, the lack of quality objective. The study has been focused on the optimization between time and cost as the result that the quality of a plan is hard to be quantified. Second, the lack of multi-objective optimization model. The single-objective network planning cannot meet the high requirement any more, however, the current study of network planning transforms the multi-objective problem into a single-objective one by setting the weight coefficients or taking several objectives as the constraint condition. Third, the separation of planning and scheduling. The resource constraints has not been considered in the study, which makes the model unreasonable and the optimization plan is of no practical use. Last, the lack of collaboration awareness. The planning and scheduling under the supply chain environment which the resource is limited has not been taken into account. Therefore, the research on the planning and scheduling model of multi-objective activity network and its optimization algorithm is of great significance.This paper is aimed at the planning and scheduling model of multi-objective activity network. Firstly, the catch-up planning model of multi-objective activity network is built. Then, the collaborative planning and scheduling model of multi-objective activity network under the resource constraints is discussed as well. NSGA-â…¡ algorithm is improved and used to solve the two calculation models at last. The main work of this paper are as follows:1. This paper builds the catch-up planning model of multi-objective activity network after considering time, cost and quality. The study which aimed at the optimization between time and cost is failed to achieve the real multi-objective optimization. This paper builds catch-up planning model for the multi-objective optimization on the basis of analyzing the relationship between time, cost and quality.2. This paper builds the multi-objective network collaborative planning and scheduling model under the resource constraints. In most cases, the study separates the planning and scheduling, and is lack of collaboration awareness. This paper integrates the planning and scheduling, resource allocation and the collaboration under the supply chain is taken into account while making the network plan based on activity. A collaborative planning and scheduling model of multi-objective activity network is built while the renewable resource and nonrenewable resource is classified for different constraint process.3. This paper improves the traditional NSGA-â…¡. While the model uses the binary encoding and critical path method, the improvements are focused on the mutation of NSGA-â…¡ algorithm and the non-critical path mutation method is proposed. These improvements can solve the convergence problems of the first model and are proven to be effective and superior by compared the simulation results with the traditional NSGA-â…¡ algorithm. A kind of punishment mechanism is designed in the choice operation while infeasible solutions exist after considering the resource constraints of the second model. And in order to retain the good feasible solutions, a feasible solution archive program is designed in this paper. The model and its algorithm are verified by the simulation experiment.