—This paper presents an Erlang reduced load model to analyze Optical Burst Switched Grid networks. The model allows the evaluation of job blocking probabilities, in which blocking occurs in both the transport network and the resources where jobs are processed. Additionally, a novel routing strategy is introduced to improve the usage efficiency of the existing infrastructure. Simulation analysis is used to confirm the validity and accuracy of the model, and the effectiveness of the novel routing strategy is shown for Grids over OBS.