It doesn't have to be a factory producing physical goods. Anytime we have a multi-stage process with different team members responsible for various stages with

It doesn't have to be a factory producing physical goods. Anytime we have a multi-stage process with different team members responsible for various stages with interdependencies, you will find constraints abound. ToC tells you that while there will be multiple constraints, your biggest bang for the buck comes from identifying the limiting constraint first and finding workarounds to break / relax that. Focusing on the non-limiting constraint would not give you the best benefit. This is such a general concept that we can apply it to so many processes whether it is sales, customer service, bug triaging/resolution, logistics etc., Any place we observe a queue (whether visible or hidden), I can guarantee that there is a lurking constraint somewhere.