Scheduling refers to allocation of limited resources to perform set of task to fulfill of certain criteria. Job shop scheduling is one of the most popular modal of scheduling. Job shop scheduling is one of widely studied and difficult combinatorial optimization problem. There are variety of disruptions may occur unexpected e.g. arrival of new job, machine breakdown etc. This paper analyzes the limitation of static approach when rescheduling in dynamically insertion of new jobs and changing environments. There are three machine and four jobs. In this research we insert two job after some time and reschedule the process. We use ant colony optimization approach for minimum makespan and maximum utilization of resource.