Cost Prediction Modelling Of Batch Production In A Manufacturing System For Sheet Metal Fabrication

To the industrial manager, the significant elements of cost involved in batch production hinge on the scheduling of the work through the production processes. The project reported in this thesis centers on the scheduling of work in the form of multiple jobs on multiple machines. Therefore the efficient progress through the production cycle will have a significant bearing on the overall cost of the product. Various methods for solving job-scheduling problems ,including both flow-shop and the job-shop, have been reviewed. In this project algorithms have been developed and tested to determine the waiting time of jobs, the idle time of machines and the elapsed time of all jobs. The number of sequences which are required to be considered in order to determine an optimal solution have been reduced dramatically by selecting pairs rather than single jobs. A forecasting technique, using economical pairs of jobs, has been developed to give an optimal or a very near optimal solution. Further, the techniques developed can find the optimal solution to both the flow-shop and the job-shop problems. Such optimal solution cannot be found by existing published methods. The mathematical models , together with quicker and easier ways of using them, are fully discussed and developed. Emphasis is given to the simplicity of the technique and the speed of calculation.