Information Technology Infrastructure Library (ITIL), a framework for IT Service Management (ITSM), emphasizes the need for an ongoing preventive activity woven into the fabric of enterprise IT of organizations as opposed to a reacting to a specific situation. However, with the increasing focus on cost reduction, it is essential to revisit the trade-off between costs and other primary ITSM objectives such as service availability and quality. With this basic premise, we compare the cost of conducting IT service operations with varying levels of prevention. We modelled the IT service operation processes based on queuing and software reliability theories while assessing the impact of exogenous variables such as initial application maturity, drop rates & monitoring cost. We illustrated that optimum lies between the extremes of complete prevention and reaction. Also, we were able to observe the pronounced impact of staffing stickiness on the results.