Completing a project on time and within budget is the dream of any project manager. However, most projects are delayed and cost overrun. This is due to process variability: unexpected shortages of people, workshop overload, equipment failures, problems with contractors and quality. Trying to tighten up your planning gets you nowhere; life still throws up surprises that aren't in the plan. The key to effective project management is taking into account variability using the critical chain method, which is developed based on Goldratt's Theory of Constraints and Deming's statistical approach. According to the author, it is quite possible to bring variability under control and achieve project completion on time even in a complex and uncertain situation. The book will be of interest to all project managers, as well as top managers who control the implementation of complex projects.