The penetration of distributed generation (DG) is increasing on distribution networks across the world. Non-firm access to the network is now being proposed as a cost effective way to facilitate DG. However, concerns remain about the operational details of non-firm access and also with regard to the financing of DG projects, which, by their nature, are not guaranteed permission to export power at all times. Here, the pertinent planning and operational issues that arise with non-firm access are analysed. The index of coincidence is used to assess the probability of constraint breaches, through analysis of historical generation and load profiles. Further to this, a novel method is proposed, which minimises the cost to the generators of non-firm access through coordinated operation.