Abstract
In a job shop the interarrival time and service time of a job are usually random, and cannot be forecasted. When many jobs (customers) arrive at a shop, the customers will hav a long wait and some of them may come back without ordeing. In order to keep out of this the shop will carry out overtime work. However, excess overtime may increase idle time of machiens and workers. In this paper what increase or decrease in quantity of arriving jobs affects the shop is investigated through a numerical analysis. Finally indicators and timing for carrying out overtiume are discussed.
