Mike Clayton gives us a short course in Critical Chain. He emphasizes on the need to focus on resources, in particular on the constraints of the organisation, rather than on tasks as in the traditional way of managing projects. He also highlights the relevancy of buffers - project buffers, feeder buffers and resource buffers - when applied to critical points of the project. Finally, with a simple example, he explains how task durations in traditional project plans can be challenged and how these can be estimated in the critical chain way so that resources can work more confidently and will more likely be able to deliver the project on time.