A computer simulation model for analysing a production system

Simulation technique is one of the well-known methods to solve problems in the real life world. It is the process of developing a model of a problem and estimating measures of performance, then performing simulation experiments on the model with different values for the decision variables in order to determine their best values. This paper is intended to use the power of the simulation technique in designing the best operating parameters for a real manufacturing system (Giza Telephone Cable Company). The computer simulation model is directed to measure the effect of changing the set of scheduling rules on the company throughput performance. The paper represents in details the objective, the assumptions, the logic of the model, the inputs/outputs, the list of discrete events used for the model, and the event flow charts. The simulation model for the system is built using the SIMPROCESS 3.1 simulation package. Three used scheduling policies are selected: first come first service (FCFS), shortest processing time (SPT), and the earliest due-date (EDD). Three factors were taken into consideration: machine efficiency, machine operation type, and preventive maintenance interval. Factorial experiments are used to design the simulation and the statistical results of each scheduling policy are analyzed using the analysis of variance (ANOVA) method and the SPSS 9.5 package. The paper represents the significant effects for various input factor levels at each scheduling rule. The conclusion shows the most significant input factors, which have magnified effect on the response average flow time.