| The mechanical product development process is affected by many uncertain factors,coupled with the complicated coupling relationship between sub-tasks,which will make it difficult for project managers to accurately plan the task duration and allocated resources based on previous design experience.The two inevitably need to make corresponding adjustments during the task iteration process,so as to speed up the task iteration rate and shorten the product development cycle.In order to study the influence of uncertain factors in the dynamic environment on the iterative duration of parallel coupled tasks and how to optimize the duration,this paper introduces the feedback control principle to feedback the task duration,task iteration status and the information dependence between tasks According to the corresponding feedback,the iterative process of each task is regulated to optimize the completion period of the coupled task set.First,in view of the uncertainty of task duration in a dynamic environment,interval membership is used to characterize the uncertainty of task duration,and based on the traditional parallel coupled iterative duration model,the duration satisfaction interval and task iteration convergence conditions are combined.The feedback adjustment matrix is used to adjust the resources of the iterative process that does not meet the time limit,so as to reduce the uncertainty of the time limit of the coupled task set.Taking the development of an air purifier as an example,the iteration results before and after invoking feedback control are compared,and the comparison results verify the effectiveness of the method.Then,based on the impact of the uncertainty of resource allocation in the product development process on the task duration,the feedback control theory is applied to construct a duration optimization model based on feedback control based on the parallel coupled iterative duration model under the condition of uncertain resource allocation.Based on the feedback results of task iteration state monitoring vectors,this model redistributes the idle resources of the completed tasks in each iteration stage in combination with the resource balance allocation method to speed up the task iteration rate,thereby achieving the purpose of optimizing the duration of parallel coupled iteration tasks.Taking the development process of an aircraft as an example,the feasibility of this method was verified.Finally,in view of the problem that information uncertainty in product development will increase the number of iterations of the coupled task set and extend its completion period,through the analysis of information variability and sensitivity,the information dependence between tasks is determined,and combined with information feedback The control intensity function obtains the calculation formula of iteration rework time of each task in the parallel coupled iteration,thereby constructing the construction period solving model of the parallel coupled task set.Through the analysis of the model,the influence of different information dependence on the rework time of iterations is obtained.Taking the development process of an automobile engine as an example,the effectiveness of the model is verified. |
