J2EE is the de-facto industry standard for implementing and scaling Java on the enterprise scale distributed systems. It is the result of strong industry collaboration. All involved is trying to make the technology J2EE commercially viable. This industry support has allowed J2EE to be based on the experience and expertise from leading designers of industry systems that are scalable, well integrated and provided a cross platform environment for application development, deployment and management. One of the major problems in building large-scale enterprise systems is managing the performance of the eventual solution. It is also true for J2EE based systems. This paper proposes an approach for accurate analysis of J2EE applications. It discusses the design of JPManager - a J2EE performance management system and related techniques, such as Java instrumentation, which is used in the JPManager?s implementation.