The Theory of Constraints (TOC) is a logical thinking process and methodology used to initiate and sustain ongoing improvement in any organisational system, including business, industry, government, health care and education.

Although TOC became a leading management theory and philosophy with its first application solutions in the mid 1980s and 90s, TOC applications continue to broaden and progress.

As a management theory, TOC was initially applied to business and industrial systems in order to generate significant breakthroughs in performance of a magnitude unmatched by other improvement methodologies.  

TOC finds the most limiting factor or constraint impeding any system from achieving its goal. Its methods then leverage the constraint to maximise throughput for the system. TOC places these systems on a process of ongoing improvement.

In order to have a process of ongoing improvement, and given that any improvement is a change, TOC examines three questions in regard to change:

1. What to change?

2. What to change to?

3. How to cause the change?

“Every improvement is a change but not every change is an improvement.” Dr Eli Goldratt.

The three questions of change:

1. What to change?

The core problem of the system. The name Theory of Constraints is based on the belief that there is a constraint for any system. Addressing this constraint, rather than dealing with symptoms, is the key to improving the entire system. TOC takes a holistic approach to system improvement.

 2. What to change to?

Constructing the solutions for the core problem and making sure they do not cause other problems.

 3. How to cause the change?

Devising the strategies and appropriate tactics to implement the solutions.

 After the third question is answered, the first question is repeated: What to change? In this way, a process of ongoing improvement is created.

In order to derive appropriate answers to these questions and achieve full consensus amongst key people who need to accept the change, a set of generic logical thinking tools was developed.

These tools aim to:

  •  Identify and define problems
  •  Find and devise solutions
  •  Construct strategic and tactical plans to achieve these solutions