Abstract: A number of recent reports have presented on the crisis in emergency departments. Many reasons were given for this. This talk looks at how routine data can be used to analyze the flow of patients and give insights into the problems, while also demonstrating some of the pitfalls in some of the analyses. There will also be a discussion of how the NHS uses (and misuses) this data both operationally and strategically. The positive and negative impact of targets will be discussed.