gh congestion on some trunks and under utilization on other trunks. This information can be easily identified from logs generated showing percentage utilization of trunks during an audit of resources. Performance reports generated at regular intervals are a key input to fore- casting those elements that would be best suited for investment on enhanc- ing existing network capabilities. The performance reports also form input to identifying the quality of service. Users are requested to give feed back on their experience of the service. The experience perceived by the user while using a service is termed as Quality of end user experience (QoE). The quality of service and quality of experience are an integral part of plan- ning and development of service and resource. Configuration of an existing network element can be used as inputs for the detailed design of a network element for a purpose similar to the existing element. EMS Functions Billing records help in identifying the services that are of key interest to sub- scribers and are used to find usage patterns and forecast the future trends and services that can capture the market. Thus billing records are analyzed and the statistical data generated from the analysis are used for service and resource planning. 4.4 Inventory Management Inventory management involves a centralized repository on network assets for track- ing and managing the assets. While a network management system gives information about a fault that occurred in the network and the resource that generated it, the inventory management system is used to map this fault to resource location, connec- tivity, affected users, service failures, and SO on. This is just a typical example of how data from the element and network management system can be complemented with functionality and data in inventory management to make a detailed map of informa- tion that can assist effective service and business management including planning. An inventory management system typically includes: Asset database Inventory ana