A Simulation Study On Production Planning And Control With Constraints Management And Workload Control

The growing competition in the global market and the consumers' increasing demand for individuality and diversity makes manufacturers to turn their production pattern from high-volume to high-mix and low-volume. As traditional production scheduling and controlling modes are mostly generated from mass-production environments, which can not well fit the coming high-mix and low-volume environments where the product mix could change rapidly. In view of these above reasons, a new type of scheduling mode is introduced based on in-depth study of the two widely-used modes namely workload control and theory of constraints.First of all, research on workload control and theory of constraints has been carried out on their basic elements and application methods, together with some comparison between them. After this, a framework and application method of the new production scheduling and control mode is discussed.Further more, to put this new mode into application, a textile & dyeing company with typical high-mix and low-volume production environments is studied with analysis on its characteristics and problems in its production. Considered the actual situation of the enterprise, a production improvement program is introduced. This consists the following six aspects including bottle-neck management, flow-path design, order review and release, buffer management and job shop dispatching, which are the key elements and implementation steps for this new production scheduling and controlling mode.Based on the above studies and some primary shop floor implementation, simulation study has been carried out on the modeling of the concrete shop-floor production system. Comparison has been made between some traditional scheduling rules and this newly proposed method, with interest being focused on several resulting aspects such as the production cycle time, product delivery, work in process and the overall system throughput. The results have shown the advantages of our method under the production environments of high-mix and low-volume.Finally, some conclusions are drawn, with some prospects being given on how to improve this proposed method in the future with some necessary further studies.