What is TOC?

I am a Theory of Constraints (TOC), enthusiast. What is TOC exactly? Here’s a quick summary.
It’s a method to identify and strengthen the weakest link (constraint), in any process in an iterative way that leads to continuous improvement. It also includes tools to help identify assumptions, constraints, and so forth. Eli Goldratt developed TOC. The organization that maintains the TOC knowledge is the Avraham Y. Goldratt Institute.
The 5 focusing steps are part of TOC. They refer to the use of TOC for continuous improvement.
1. Identify the constraint
2. Use the constraint to your advantage. It will directly increase the throughput of all the system.
3. Everything should be subordinated to the above decision. If necessary, change habits and policies to ensure you get the most out the constraint. No more “This is how we’ve always done things.” Don’t add more work to the system than the constraint can handle. It just builds up work-in-progress (WIP), in front of the constraint. If the machine is just adding WIP to the constraint, it’s not the right thing to do. Change your mindset ….we are looking for global optimization, not local optimization. Nothing is sacred but the goal of global optimization.
4. Increase the constraint Accelerate the bottleneck
5. Once the constraint has been broken, go back to step 1. “Breaking a constraint” means that you have improved the bottleneck until it is no longer present in the system. Don’t let new policies and processes become a roadblock to future improvement. Restart step 1 and go back!
Here’s a TOC concept illustration from TOCCA