The Crown Commercial Services have published a new PPN 05/16 on open book contract management (OBCM). OBCM is described as the scrutiny of a supplier's costs and margins by accessing accounting data. The intention of the PPN is to ensure that a proportionate and consistent open-book approach is applied to a broad range of contracts. Its use is often associated with managing and controlling delivery of large, high-value, high-risk and complex contracts.