A service provisioning and activation method and system for telecommunications networks. The system operates in between a business support system (400) and a plurality of network element (480) and comprises a service repository (450) containing service configuration data. The system comprises also an order management component (410), which includes a generic logic (412) for service provisioning and activation operations, and an operation specific functionalities module (414) comprising operation specific functionalities capable of using data from the service repository (450). The order management component (410) receives requests from the business support system (400) and processes it according to the generic logic (412) calling the operation specific functionalities in the operation specific functionalities module (414). By means of this configuration, the system can perform a request-specific series of operations based on the received request and the data from the service repository, without the need of programming individual workflow for each different service activation, deactivation and modification situation possible in the telecommunications network.