Enterprise Java Beans (EJB) are one such tool that developers can choose to help them simplify the technical aspects, allowing them to focus more on the business requirements. However, as the enterprise solution is developed and constrained, there are several factors that need to be determined but are unknown at this early stage of development. Modeling these systems to predict the unknown is a possible solution that can save both time and money. However. as hardware and architectural aspects change over time, the model may need to change as well, which may be a very difficult task in the case of large systems. This paper presents the use of EJB templates of Layered Queueing Networks to handle the change for both the software and architecture of the SPECjAppServer Business Case. In this work, two LQN models have been developed and their results have been discussed.