Continuous increase in the share of renewable energy sources and other low carbon units complicates the planning and operation of distribution networks. However, the newly created complexity also presents an opportunity for Distribution System Operators (DSOs) to start using the tools developed by the researchers and industry that will enable easier planning and operation of smart distribution networks. One such set of tools, named SENS (Smart Energy Network Systems), is presented in this paper. SENS enables four different applications in the planning (proposing an optimal topology of a distribution network) and operation (distribution network reconfiguration, calculation of flexibility provided by DSO’s assets, and flexibility provided by a third party). We present a proof of concept in which four developed and implemented functionalities are verified and tested on different case studies defined in medium voltage distribution networks.