Research On Production Scheduling Of Prefabricated Building Components Under Uncertain Events

Currently,the promotion of prefabricated buildings faces many challenges.For example,industry policies and regulations are not perfect,market awareness is insufficient,product forms are single,and so on.Among them,the prefabricated construction is more costly than the traditional cast-in-place construction method and the component production delivery time cannot be fully consistent with the on-site component demand time.Realizing the on-time delivery of components is an important basis for promoting prefabricated buildings and an important guarantee for industrialization of buildings.Given to the importance of timely delivery of components,the academic circle gave birth to a series of research on component manufacturers.As an important part of the construction industry,component manufacturers are a Make-to-Order company,so the production of components can be optimized to ensure on-time delivery of components.It is beneficial to reduce the production cost of component manufacturers as well.However,the production and delivery of components involves both the constructor and the producer,and the components have characteristics of onetime production and customization.All above factors lead to frequent occurrences of uncertain events in the production process,which interferes with the production process and resulting in the production cannot be carried out according to the original plan.Therefore,a reasonable production scheduling scheme is needed to cope with the impact of uncertain events.The paper mainly does the following work.Firstly,it analyzes the production characteristics of the component manufacturing enterprises and the current production scheduling status,and adopts the flow shop scheduling for the component production scheduling.After thoroughly summarizing and categorizing literature,the objective functions and constrains of component production scheduling are obtained and initial production scheduling model is then established.Secondly,the paper systematically sorts out and summarizes the uncertain events on components production.What's more,we divided it into external uncertain events and internal uncertain events according to whether it occurs within the control of the component manufacturing enterprise.Thirdly,the rescheduling method is adopted to deal with the uncertain events in production,and a hybrid driving mechanism based on the latest completion time is proposed.Different types of uncertain events adopt different driving mechanisms and different rescheduling methods.Finally,the rescheduling model under uncertain events is established.That is,for the external uncertain events,the event driven strategy and local rescheduling method is adopted;for the internal uncertain events,the hybrid driving mechanism based on the latest completion time is adopted,and the complete rescheduling method is adopted.Finally the production rescheduling model under the uncertain event is established and the model is solved by genetic algorithm.The paper provides a reference for the multi-project production optimization scheduling problem of prefabricated components,helping enterprises to develop a reasonable production scheduling scheme,which is beneficial to enterprises to improve production efficiency and ensure on-time delivery of prefabricated components in a shorter time and lower cost.In short,the paper not only has important practical significance for improving the production management capability of prefabricated component manufacuturer,but also has important significance for advancing prefabricated buildings.