Deals with dynamic scheduling problems and solutions of job shop comprising six work centres and n components. Concerns the behaviour of the system, with the arrival of urgent orders and normal orders. In a typical manufacturing system, urgen orders are scheduled for processing based on their urgency and given priority over normal orders. Describes an analysis of urgent order processing on the basis of non pre-emptive priority and pre-emptive resume priority over normal orders. Enumerates manufacturing system performances which had been analysed for the two most popular scheduling rules-first in first out and shortest processing time-through a system simulation program. Concludes by asserting that the simulation program can be used to schedule the manufacturing system dynamically by choosing the appropriate scheduling rule to measure optimal system performance leading to higher productivity.