Estimating the effort required in resolving an incident for a production support engagement has been a long standing problem. Although, a lot of work has been done in software engineering field in estimating effort required for software development, there is no adequate body of work on production support effort estimation. Reliable effort estimates for handling each kind of incidents can have the benefits of planning the complete project engagement for many services firm which thrive on production support projects. In this paper we are presenting a framework for estimating mean effort required to resolve an incident. The simulation model is based on agent based modelling approach to capture the attributes and interaction of the agents. We have also tested the framework with few policy experiments to test the amount of effort required to resolve the incidents and its impact on SLA compliance. The model has been tested against real industry data and looks to fill a large gap in providing managers of the services firm with a reliable tool to conduct policy experiments and in turn better utilize the resources.