  The increased flexibility requirement needs a flexibility market at the
distribution grid level operated by the distribution system operators (DSOs) to
resolve challenges to ensure secure operation and, to integrate new renewable
productions or loads in the grid. Therefore, the network visibility and
monitoring are paramount to distribution network operation. This paper presents
a methodology demonstrating the value distribution grid monitoring can bring
for the realisation of a local flexibility market. This paper further
illustrates the reduction of costs of operation of a DSO with the help of grid
monitoring and local flexibility market while maintaining a secure and reliable
operation. The methodology has been applied on a real 35 node MV network of a
Swiss DSO with several GridEye measurement devices. The performance in terms of
losses and voltage and flow violation costs is compared with sub-optimal
operation without monitoring.
