1. A computer-implemented method for determining an effect of a proposed configuration change on a transaction basis to at least one element in a distributed computer system comprising the steps of: initiating a set of instrumented synthetic transactions in the distributed computer system; tracking access to managed resources by synthetic transactions to produce a list of utilized resources for the transactions; categorizing the utilized resources according to criteria including associating the utilized resources with respective transactions; repeating the initiating, tracking, and categorizing steps after a proposed configuration change using a selected subset of the set of transactions, wherein respective members of the selected subset of the set of transactions are selected by identifying transactions which access the utilized resources affected by the proposed configuration change; benchmarking the distributed computer system having a changed resource using synthetic transactions to produce a changed configuration benchmark compared to a prior configuration benchmark of the distributed computer system measured prior to the configuration change; and displaying a comparison of the changed configuration benchmark and the prior configuration benchmark.