ty provisioning, dynamic SLA-based provisioning, monitoring provisioning and any other setup activities that will be required to pro- vision a product package consisting of multiple or at least one service, which is described as an order. An operation support system will usually consist of multiple provisioning modules specialized for a specific activity. Provisioning with minimal or no manual intervention is a goal that most service providers try to achieve in their OSS to bring down the OPEX. The inventory management system supports and interacts with multiple mod- ules relevant to fulfillment by keeping track of all the physical and logical assets and allocating the assets to customers based on the services requested. Order man- ager interacts with inventory manager (IM) to check if sufficient inventory exists to complete an order. The purchase and sales module updates the IM with new assets added, old assets sold, assets given to an outside party on rental, and assets that were borrowed from a third-party vendor. Provisioning module interacts with IM to work on allocated resources and also for updating the status of allocated resources. The next module that gets feed from IM is the network manager. The network manager contacts the IM to get static information on the resources being monitored and managed by the network manager. Provisioning system Provisioning commands Network and Network and Network and Management element element element plane managers managers managers Communicate with component APIs Infrastructure Wireless Access Transport plane components components components Figure 20.4 Provisioning OSS. Fundamentals of EMS, NMS and OSS/BSS The network manager user interface will have the capability to display the attributes of the resources being managed. The value of some of these attributes can be queried from an IM module. Inventory management is mostly automated with minimal or no manual entries. This is because small errors while manually feeding inventory data can result in major trouble condition