To be able to gain knowledge from the past in complex, dynamic systems their factual functioning should be transparent. Understanding deficiencies and systemic deficiencies ought to be produced from analysing decision-making and underlying assumptions, uncertainty and understanding. Such deficiencies should be identified through the design process in addition to during operational practices, to be able to facilitate systems change and enhancement from the safety performance. Safety investigations should facilitate evidence-based learning. With no fact-finding mission coping with on-site observations and interpretations, evidence-based learning is going to be missing and having consensus will disappear to some mere settlement result. Supplying evidence may be the domain of forensic sciences. By supplying a prompt transparency, safety investigations might take the function of supplying functional needs for that (re-)engineering style of resilience like a system property. This method is shown by two major situation studies which have been conducted within the Netherlands: the El-Al air crash in Amsterdam and also the inquiry in to the High-speed Line ERTMS signalling system.