| As one of the important components of steel structure building industry, the steel structure manufacturing enterprise is a kind of order oriented enterprise, which integrates design, manufacture, installation and service, and it is also called project type manufacturing enterprise. The steel structure production management is of characteristics with random order, multi project operating at the same time, customization, disposable products, large body type and complex production, which determines process many uncertain factors in the production and these uncertainties often lead that production can not match the plan for execution. Therefore, it is necessary to reasonable production plan and control to eliminate the influence of uncertain factors, to ensure the project smoothly. The main work of this paper is as follows:(1)This paper introduces the characteristics of steel structure manufacturing enterprise, and analyzes the present situation of optimization scheduling of multiple-project production and the uncertainty factors existing in the production process. Then it points out steel structure of multi project production scheduling characteristics in the uncertain environment, and constructs the framework of steel structure multi project production scheduling in uncertain environment;(2) In the initial scheduling model it mainly considers the common scheduling goal and multi project scheduling objectives at the same time, combining with the characteristics of steel structure enterprise production, and builds the steel structure of the initial project scheduling model, meeting the constraints of the project process, equipment and space resource, which sets a goal of steel structure of multi project production scheduling by advancing or delaying time penalty. In interference scheduling model, it proposes a way of considering metric perturbations among customer, enterprise managers and workers in the workshop, combining prospect theory with fuzzy theory to construct unsatisfactory membership function to measure the size of human behavior disturbance, then it constructs steel structure project multi-objective interference scheduling model;(3) In view of the demand characteristics of the steel structure multi project initial scheduling model and the interference scheduling model, a multi group cooperative particle swarm optimization algorithm based on entropy is proposed to solve the problem. In order to maintain the diversity of the solution in the scheduling process, it is mainly depended on the population entropy to regulate migration factor size which guides the direction of particle motion. In order to improve the speed of the solution in the scheduling process, the dynamic adjustment strategy will be adopted to improving the speed of the algorithm;(4) Considering the previous buffer time setting will affect the critical chain, this paper sets free time as feeder buffer for the activities of non-bottleneck resources, and sets disperse capability buffer constraints as buffer capacity for the bottleneck resources activities, then builds project buffer at the end of each sub-project. On the basis of this, the paper puts forward a dynamic buffer monitoring model, aiming at the situation that the degree of uncertainty of the project is gradually reduced. According to project execution, the model mainly adjusts the size of project buffer and capacity buffer in dynamic, and sets point monitoring and adjusts trigger points in dynamic, so as to ensure a warning information and project practical implementation in line. |
