Transport networks provide reliable delivery of data between two end points. Today's most advanced transport networks are based on Wavelength Switching Optical Networks (WSON) and offer connections of 10Gbps up to 100Gbps. However, a significant disadvantage of WSON is the rigid bandwidth granularity because only single, large chunks of bandwidth can be assigned matching the available fixed wavelengths resulting in considerable waste of network resources. Elastic Optical Networks (EON) provides spectrum-efficient and scalable transport by introducing flexible granular grooming in the optical frequency domain. EON provides arbitrary contiguous concatenation of optical spectrum that allows creation of custom-sized bandwidth. The allocation is performed according to the traffic volume or user request in a highly spectrum-efficient and scalable manner. The Adaptive Network Manager (ANM) concept appears as a necessity for operators to dynamically configure their infrastructure based on user requirements and network conditions. This work introduces the ANM and defines ANM use cases, and its requirements, and proposes an architecture for ANM that is aligned with solutions being developed by the industry.