1. A method of preparing a discrete event simulation model of a production network including a client and a plurality of servers on a plurality of network tiers connected by a network comprising the steps of: executing a business function from the client on the production network; gathering resource data from the plurality of servers; normalizing the resource data; calculating a consumption of resources used by the plurality of servers; estimating a transaction cost associated with the consumption of resources; and building a discrete event simulation model from the transaction cost.