In order to explore the applicability of diagrammatic representations for healthcare systems design, this paper aims to investigate the roles of different diagram types in various healthcare systems design cases: medication management process; medical device purchasing process; patient diagnosis process. It mainly examines how healthcare workers perceive various diagram types in terms of ease of understanding and utility. In conclusion, it provides insight into how to use various simple diagram types for healthcare systems design.

Background: Prescribed medicines are delivered through a variety of routes to patients in the UK National Health Service (NHS) and are regulated by a host of health and trade related policy and law. These ensure the efficient and safe supply of medicines of appropriate quality from the pharmaceutical manufacturer through to the end-user, the patient. However, persisting medication errors and the recent discovery of counterfeit medicines in the bona fide supply chain have meant there are growing concerns about the timely, accurate and safe supply of medicines in the NHS. Methods: This study undertakes a systems design approach to process modelling and understanding three key supply routes from the manufacturer through to the patient, across both primary and secondary care. A systems design approach was deployed to investigate complex interactions between professionals, products and processes to improve patient safety in collaboration with twenty five clinical and nonclinical stakeholders across the supply chain and six enduser patients. Results: Several system process models were developed from the literature, field observations and alongside the interviewees. The results reveal that risk to medication safety is perceived as occurring most at the patient-end of the medicines supply chain: the pharmacy and the ward. There are differences observed in the responses of interviewees when they engage with system models. Conclusions: This paper reflects on the use of a systems design, a mainly engineering approach, to understanding a health care domain problem of medication errors. The approach provided an enhanced insight into the complex set of system factors and interactions involved in generating medication errors. This study is among the first to develop a systems-wide view of the medicines supply process 'as-is' and identify opportunities for re-design to improve patient safety.