3. Results and discussion
This section presents and discusses the results of the simulation study described in the preceding section. The performance measures recorded are the time in system, the shop flow time, the percentage of tardy jobs and the standard deviation of job lateness. Time in system is used as an indicator of balancing performance of the order release mechanism and refers to the time a job spends waiting in the pre-shop pool plus the shop flow time. The benefits of reducing time in the system are related with reducing the overall response time to customers. The shop flow time refers to the time that elapses between job release and job completion. Reducing the shop flow time has also intrinsic benefits, which implies a smaller WIP(work in process) and therefore reduced costs of tied-up capital. The percentage of tardy jobs refers to the fraction of jobs that is completed after the promised due date. The standard deviation of job lateness is a measure of how spread out a lateness distribution is. It is used as an indicator of timing performance, i.e. it indicates how close to due dates the completion of jobs are.