nvergence of both fixed and mobile termed FMC (fixed mobile convergence). On the business front, prices were falling due to competition and there was a demand for higher return on investments. This new landscape brought in different needs for each of the tele- com players. The suppliers wanted to have standard interfaces for interaction to reduce the integration costs and ensure that there is a higher chance for operators to buy a product that will easily integrate and interoperate with other products. The operators wanted to reduce service life cycle and achieve minimal time to market by reducing integration time. Another important need of the operator was to reduce the operating cost and spending on OSS. To meet the needs of the key players, the OSS expected to offer rapid service deployment, customer self-care strategies, flexible real-time billing models and sup- port for the multiservice, multitechnology, multivendor environment. The business Fundamentals of EMS, NMS and OSS/BSS models and systems available were not able to scale up to these new requirements. The suggested solution was to change the approach toward management solution development in a way that will ensure that OSS solutions can: Adopt changing business models and technologies. Reduce CAPEX and OPEX on OSS/BSS. Integrate well with existing legacy systems. Offer integrated billing. Can function as off the shelf components. Offer flexibility, interoperability, and reusability. NGOSS, driven and managed by TeleManagement Forum, is the new approach that meets these challenges using a set of well-defined methodologies and practices. Key elements of this approach include a business model, system integration archi- tecture, information model, and an application map. This chapter first outlines NGOSS concepts, the life cycle showing a holistic telecom view, NGOSS adop- tion methodology, and the NGOSS key focus areas. The TMF offers a collabora- tive environment where service provider's work closely to solve their business and technical issues using N