This thesis is a study into an engineering technology that enables us to investigate the cognitive aspects of systems. Where previous techniques have focused on individual human roles undertaking defined tasks, this work develops engineering technologies to understand the cognitive contribution of the human team participating in the system and how the deployment of machine decision making technologies can influence and change the possible human contribution in that system. This work first develops a framework for understanding an individual’s cognitive focus and then an engineering process that enables us to model the individual human cognitive contribution to the system and by combining these models to create a rich system model. This model can then be used to consider the deployment of advanced machine technologies, to identify new human or machine interaction requirements that are focused on maintaining the effectiveness of the human contribution. It then operationalises and verifies these engineering techniques by applying them to two systems. The first study chosen took an existing system whose effectiveness had been changed by the deployment of machine automation which has known problems; the use of the framework enabled the prediction of these problems and the identification of potential solutions. The second study investigated an existing human system and the potential deployment of machine technology. This study used the framework to create models of the human cognitive focus and joined them together to form a rich system model, into which the deployment of the machine technology was considered. This resulted in the ability to identify the impact of the machine technology across the entire human team, enabling the identification of additional requirements to support the human cognition and to maintain human knowledge.