HIPPO provides an optimization framework for solving security constrained unit commitment (SCUC) problem in RTO/ISO day-ahead market. The innovative features of HIPPO are: 1. Decomposition algorithms based on relaxing system couple constraints such as power balance constraints and transmission constraints. 2. Decomposition algorithms based on relaxing temporal decoupling inter-temporal constraints. 3. Concurrent optimizer executing multiple algorithms simultaneously and leveraging each algorithm's best performance