Evaluation of optimum combinations of spreading and cutting machines in a garment factory

This paper proposes a two-level model by using a nonlinear integer programm ing model and queuing theory with the Kendall-Lee A/B/C/D/E/F notation to a ssist garment manufacturers to evaluate their existing combinations of spre ading and cutting machines installed in the cutting floor. The first level is a nonlinear integer programming model to determine the optimal number of spreading and cutting machines constrained by a given arrival rate of jobs and the service rate of the machines. The second level is used to determin e the total cost of delay with the proposed number of machines which is giv en by the first model. In order to obtain the solution of this two-level mo del, M/M/1/GD/c/infinity and M/M/s/GD/c/infinity queuing theory models are applied on the second-level model and case studies are used to illustrate i ts application. The proposed approach is worthwhile for those manufacturers who intend to make a big investment in automation on their cutting floor.