Systems in oil and gas operation, such as marine operations and topside processing, are exposed to unpredictable environmental conditions and operational risk. Complexity in operations, software systems, sub-systems and components is increasing and current decision support systems are insufficient. For the operator to achieve full situation awareness, prediction of incidents, near-misses, and accidents is needed, as well as an improved understanding of the current situation and on how to act. The suggested concept and framework in this article can be installed in parallel with existing systems, such as automatic on-board control systems, to supply systems with independent, early warning of possible accidents or incidents. Advances in estimation and data assimilation are important to bring into online risk management development. The system is illustrated with reference to application for a Floating, Production, Storage and Offloading (FPSO) system, but may be applicable in several areas.