The complexity of policy-making in the NHS is such that systemic, holistic thinking is needed if the current government's plans are to be realized. This paper describes systems thinking and illustrates its value in understanding the complexity of the diabetes National Service Framework (NSF); its role in identifying problems and barriers previously not predicted; and in reaching conclusions as to how it should be implemented. The approach adopted makes use of soft systems methodology (SSM) devised by Peter Checkland. This analysis reveals issues relating to human communication, information provision and resource allocation needing to be addressed. From this, desirable and feasible changes are explored as means of achieving a more effective NSF, examining possible changes from technical, organizational, economic and cultural perspectives. As well as testing current health policies and plans, SSM can be used to test the feasibility of new health policies. This is achieved by providing a greater understanding and appreciation of what is happening in the real world and how people work. Soft systems thinking is the best approach, given the complexity of health care. It is a flexible, cost-effective solution, which should be a prerequisite before any new health policy is launched.