Let's say you're putting together a custom RPG system of yours (core mechanics of dice and conflict resolution, support mechanics, the skills, the races, the fluff, etc.)
Let's say you're making a fairly conservative system - something DnD-ish, fantasy-ish.
Let's also say you're not all that skilled and/or experienced at this kind of a designer job ... and you botch your RPG system.
Now, how do you objectively determine whether your system is broken? And, more importantly, how do you objectively define the criteria for the system possibly being so bad it only deserves to be thrown away, as a whole (as opposed to fixing a couple of elements and hoping for improving the functionality of the system)?
Why am I asking this? When I get my hands on a bad system design, I do get this gut feeling of the system being broken. Gut feelings are nice and all, but they do not translate to the other person. More rigorous approach is desired.