The Theory of Constraints (ToC) is based on ideas of Eliyahu M. Goldratt and deals with the question of how to maximize the throughput of a system. The basic insight of the solution approach is that every system has exactly one bottleneck, which, similar to the narrowest point in a pipe power system, limits the throughput no matter how much you put into the system at the front end. The system is optimized as follows:Identify the bottleneck. There are never two bottlenecks unless we are dealing with completely independent systems or value streams. However, we consider each system separately.Utilize the bottleneck optimally. This is almost never the case beforehand. Often, attempts are made to increase local efficiencies at all possible points in the system. But this only leads to an improvement in the overall system if it happens at the bottleneck. All other improvements are irrelevant for the overall throughput! Align the management to the bottleneck, i.e. subordinate all activities to it. All points in the system or in the company or project should work in such a way that the bottleneck - this can be a machine or a person or a team - is as fully utilized as possible, has no idle time and can concentrate on one main task. Everything else is a waste! Expand the bottleneck. Only when the bottleneck is used optimally and the throughput of the system is still not high enough, do we expand it, e.g. by buying another machine or adding personnel to the bottleneck team.Start again at step 1.When the bottleneck is expanded or fully utilized, there is often a shift, because the overall system now has a bottleneck again. This can be the same bottleneck or - more likely - a new one. A project management method based on the bottleneck theory is the so-called Critical Chain Project Management. Source: Alexander Kriegisch, Scrum-Master.de See also: Wikipedia - Theory of ConstraintsToC4U - Series of articles about the ToC