I stole the following from a TOC website that I've promised not to mention here (just yet).
"Some people have a problem with the word theory. As in; "this is just a theory, but I deal with reality." Well a theory is a way to describe reality. We can't increase output by 45% or profit by 90% or reduce lead time by 66% using fiction. However, if the "theory" in the Theory of Constraints title is bothersome, then please substitute in the term "reality" as in the Reality of Constraints. Constraints are real unless we are making infinite amounts of profit. We can choose to manage the constraints or choose to allow the constraints to manage us. Conversely we can choose to ignore the constraints, but rest assured that the constraints will not choose to ignore us. The constraints will dictate the way that our organization performs. In other words the constraints will impact upon us regardless of whether we know it or not, and we will also impact upon the constraints regardless of whether we know if or not. So it is best to know it, to acknowledge their reality."
The point is that the constraints are there whether you know it or not. This is the reality of constraints.
