Research On Scheduling Management Of Research And Development Project For Mechanical Product

Increasingly intense global competition is calling for higher and higher product development efficiency of machinery manufacturing enterprise. Thus, it has become an urgent problem to find out the way to shorten project cycle of product development and accelerate the speed to push new product into market. But at present, about70%of the research and development (R&D) project in the enterprise can’t be completed on time. As a result, the new product can’t be pushed into market as planned, missing the best opportunities. One of the most fundamental reasons leading to this problem is that the project schedule is usually developed by project managers according to their experiences during the product R&D project management process, which leads to strong subjectivity of task decomposition, ignorance of coupling iteration between tasks, resulting in the inaccuracy of logical order and duration estimation. The project will be delayed due to the poor enforceability of the schedule, where occurs too much task iteration, resource conflict and task delay.75%of design activities are based on case in the machinery manufacturing enterprise, which is to say that most product R&D projects are based on variant design. For those projects, the data and information, providing basis for creating the schedule, is known before the project is started, such as product R&D process, basic composition of product structure, skill requirements for parts design. Therefore, the method of developing machinery product R&D project schedule is proposed, which is based on the data and information such as product R&D process and product structure tree. In this way, the project schedule will be more consistent with actual R&D process and executable, with less subjectivity and more scientificity.In mechanical product R&D projects, the tasks of work breakdown structure (WBS) can be decomposed according to the product R&D process, the product structure and the deliverables, based on which, a product R&D WBS decomposition model is proposed. A specific R&D task decomposition process is put forward, and the identification generation rules of R&D task are defined. According to the hierarchy and complexity of the product structure tree, a decomposition method of parts R&D task based on product structure tree is presented. The mapping rules between components and tasks are developed. The mathematical models of mapping and the process of mapping algorithm are established. The automatic WBS decomposition based on product structure tree is achieved, and the standardization, efficiency, and accuracy of the R&D project task decomposition is improved.Considering the hierarchy of WBS, the modeling method based on DSM is proposed to clearly describe and conveniently analysis the information interaction between R&D project tasks, which realizes the construction of DSM corresponding to any level or part of tasks and the extension of models with the step-by-step evolution of R&D process, reduces the modeling difficulty and improves the modeling efficiency. On the basis of modelling with hierarchical DSM, the planning and sequencing of coupled task sets is researched. The recognition method of coupled task sets based on reachability matrix is presented. The merging and reorganizing strategy of coupled task sets based on clustering methodology is put forward. The tearing algorithm of coupled task set is proposed to realize planning and sequencing of the coupled tasks, which is based on dual order indexes--number dependence and information dependence.In order to solve the problem of task duration predicting in R&D project with poor information, small sample event and uncertainty, a method based on grey prediction model of amplitude compression is put forward to predicting the duration of coupled task set, in consideration of discreteness and oscillation features of coupled task set duration. The smooth operator is used to enhance the degree of oscillation sequence. The discrete grey prediction model DGM(1,1) for oscillation sequence is established, and the steps of grey prediction for coupled task set duration is set up. The prediction method will reduce the effect of grey factors in coupled task set duration prediction, and improve the accuracy of duration prediction.Generalized precedence relations (GPRs) exist between tasks in product R&D project, including four sequential precedence relations as start to start, start to end, end to start, end to end. Each of these relations contain minimum and maximum lags requirement. Accordingly, Multi-mode flexible resource-constrained project scheduling problem with consideration of GPRs between R&D tasks is studied. The time window of task start time with GPRs is analyzed. The mathematical model of multi-mode flexible resource-constrained project scheduling problem with generalized precedence relations is established, and a genetic algorithm is proposed to solve the model. The corresponding encoding and decoding method is presented. Then, the start/end time, the execution mode and resource allocation scheme of project tasks is identifies. The project schedule development is finished and the executable project schedule whose duration is shortest is obtained.At last, based on previous theoretical research, the operation flow of R&D project scheduling management is analyzed. The system structure of the product life cycle management system is extended. The main functional modules of project scheduling management is developed, and was successfully applied in an offset wind turbine R&D project.