I am, of course, more of a strength athlete than I am a bodybuilder. So for me I program what I wanna lift and divide the time I have until a competition and, unless I fail, I tend to hit the numbers. That's more or less how all strength athletes (the sensible at least) do what they need to do.
Now with a bodybuilder it's less the number and far more the stimulus. The ability to contract the muscle hard or to create as close to a muscle cramp as possible while stretching and flexing is everything. Yet a few notches down from that, with just a pump and burn, is - in the long term - probably the way most will succeed.
True failure, in both strength training or bodybuilding is rare. Go watch a Tom Platz video or read a description of how, by the end of his sets, he was barely moving and you'll have an idea.
When you look at the science of muscle stimulus it's very close to what Dorian Yates suggested. Some volume IS required but not loads.
I can and I have taken the old training buddy through some very quick hard full on to failure sets. Most trainees would NOT like to train this way. It's just brutal. There's a hint of the Arthur Jones about it - here's a sample idea.
Chest:
Flyes (pec dec or dumbbell - use an incline bench). Warm up sets x 2. Then an all out 15-20 reps at 70% of 1RM.
- walk them over to the following - it must be prepared in advance - there's NO rest.
Dumbbell, barbell or a hammer style leverage bench press. Select from flat, decline or incline. Use smaller plates to load the machine. They will start with 70% of 1RM and do reps til failure. Pull some plates off (down to 50-60%) rep, then down to 40-50%. Rep.
If there's anything left have them flex the chest. Feed then kick out of gym lol.
Nautilus used to make what was called the 'duo' range. One was a pec dec and decline bench type machine. Prototype versions used the legs to assist in negatives (leg ext style set up to raise the stack). Feel free to try some negatives as a part of the above suggested workout.