Theory of Constraints (TOC) is a systemic approach to improvement that identifies inaccurate underlying assumptions and implements simple solutions. Some common inaccurate assumptions include that everyone must always be busy, buying in bulk is cheaper, and estimates are imprecise. TOC seeks to identify the underlying constraint causing negative effects, implement a common-sense solution, and change rules accordingly. It provides principles for production, distribution, project management, and conflict resolution by addressing inaccurate assumptions and behaviors resulting from them.