My weekly Google Alert for Theory of Constraints popped up this One-Minute Take-Away on The Goal. The brief article gives you this graphic and then a brief explanation. Not bad.
I sometimes struggle with finding the best explanation for "what is Theory of Constraints" and often come back to something similar to this. Every system has one constraint. If you know where it is, you can do something about it. Either focus the business (or any system) around the constraint, so you aren't wasting resources where they won't help. Or decide to move the constraint elsewhere by eliminating the current bottleneck. Happily, this still results in focused effort AND on getting more out of the system: getting more of your goal.
[Unfortunately, I have no idea of the owner of this article, given that the website doesn't offer any personal attribution. The topic is good, I just don't know if they are the owner. There is a link to Frank Patrick's Focused Performance, so that gives me come comfort.]