Theory of Constraints (TOC) is an overall management philosophy. Dr. Eliyahu M. Goldratt introduced the theory of constraints in his seminal 1984 book entitled ‘The Goal’. It is based on the application of scientific principles and logic reasoning to guide human-based organizations. The publicity and leadership behind these ideas has been dominated by Dr. Goldratt through a series of books, seminars and workshops.
According to TOC, every organization has – at any given point in time – at least one constraint which limits the system’s performance relative to its goal. These constraints can be broadly classified as either an internal constraint or a market constraint. In order to manage the performance of the system, the constraint must be identified and managed correctly (according to the Five Focusing Steps below). Over time the constraint may change (e.g., because the previous constraint was managed successfully, or because of a changing environment) and the analysis starts anew.
The Five Focusing Steps
One of the most important process of the Theory of Constraints is based on the premise that the rate of goal achievement is limited by at least one constraining process. Only by increasing throughput (flow) at the bottleneck process can overall throughput be increased.
The key steps in implementing an effective process of ongoing improvement according to TOC are:
0. (Step Zero) Articulate the goal of the organization. Frequently, this is something like, “Make money now and in the future.”
1. Identify the constraint (the thing that prevents the organization from obtaining more of the goal)
2. Decide how to exploit the constraint (make sure the constraint is doing things that the constraint uniquely does, and not doing things that it should not do)
3. Subordinate all other processes to above decision (align all other processes to the decision made above)
4. Elevate the constraint (if required, permanently increase capacity of the constraint; “buy more”)
5. If, as a result of these steps, the constraint has moved, return to Step 1. Don’t let inertia become the constraint.