It's intended to give an approximation to the Theory of Constraints (TOC), to achieve that goal we explain the conceptual bases, the thinking process, the flow management and later on we will focus on its application into production, also known as DBR (Drum-Buffer-Rope). A usual critic in the academic environment is that TOC techniques produce results that are feasible but not always optimal. Although defenders of TOC reply that optimal results are very elegant but need to reduce or eliminate variability of systems, while TOC is an appropriate method to work with variable worlds, such as the real one. Anyway, this creates a gap relative to production programming and sequencing, establishment of batch sizes, measures of initial buffer size and determination of the optimal product mix.