The dynamic job shop scheduling problem has been studied extensively during the last two decades. Because of the complexity of the dynamic job shop scheduling problem, numerous simulation studies have been conducted and published in the area. These studies fall into one of the following categories: the studies comparing and/or developing scheduling rules which will give good shop performance under a given set of job and shop parameters, and the studies investigating sensitivity of shop performance to job and shop parameters under a given set of scheduling rules. In the literature, shop performance has been evaluated in terms of (1) criteria based on job completion times, (2) criteria based on due dates, (3) criteria based on costs. This paper discusses approaches taken in major simulation studies of dynamic job shop scheduling problem according to the above classification.