Just interested really. I started brewing 3 months ago and have been beavering away with 4 fermenters to get a nice little pipeline. I'm at a point where I have maybe 15 gallons bottled and another 7 in the fermenters. This seems to be enough to allow a choice of several beverages at any time and allows normal gravity beer enough time to age a little so it's not being consumed while green. Plus not having to rush anything through at any stage.
This is an ok size for me. I'll keep collecting bottles and start putting down some higher gravity stuff that I can store away and forget about for 12 months, but I wouldn't want a pipeline so big that stuff starts going past it's peak.
What sort of pipeline does everyone else keep going?
I have: 7.5G Fermonster, 4x 6G fermenters (2 glass, 2 PTE), 5x 3G fermenters (better bottle), so total of, lets just call it 45G of fermenting ability (not counting kegs). Plus 2x6G buckets, but I barely use them - only if all fermenters are tied up, which is rare. Plus a few gallons of mead and kombucha, but that's a minor correction.
I have 8-keg, 8-tap keggerator that I built, but I have 10x 5G kegs and 3x 2.5G torpedo kegs. So my kegging capacity is 57.5G, and serving capacity is about 45G. Plus of course bottles.
My bottleneck is on serving/consuming side, obviously. I almost always have all 7-8 keg capacity on tap, probably closer to 30G of actual beer out of ~45-50G keggerator capacity, since many kegs are about half full (or half empty if you are that kind of person).
I brew 10G (sometimes 15G, on occasion 5G) batches and I usually have about 10G actively fermenting, in my fermentation chamber, plus another 10G or so "aging" at ambient and currently 5G of sour beer that will keep fermenting for 8-12 months. By the way, I usually split 10G batches into two 5G batches, or even one 5G and two 2.5G, or four 2.5G batches, and do different experiments - hops, fruit, oak, cocoa, nitro, peppers, bourbon, wine additions, you name it. Which is why I have 2.5G torpedoes and 3G fermentors.
I definitely agree with "stockpile" vs. "pipeline" discussion above.
It gets a bit tricky with sours (take forever) and lagers, but with ales, my pipeline could be similar to what Gameface described - about 40G a month (for me, assuming 1 week in fermenting chamber, which can take 10G, and then another week or slightly more in ambient).
My stockpile is (excluding bottles/growlers, which I also have dozens of gallons of) limited by my keggerator, which is also about 40G or so. So it takes a month to completely refill my "stockpile" if it ever runs dry.
The limiting factor of course then is consumption. I think I consume only about 20-25% of my beer, my neighbors, friends etc. do the remaining part.
Even then we never approach 40G theoretical limit per month (means I would brew 10G batch every week to keep up).
Currently I have a keg full of beer sitting outside of the fridge and two other fermenters that could have been transferred into kegs a week or so ago, except there is no room in keggerator. So they are still "aging". I think consumption rate is about 10-15G per month, which means I can brew 1-2 times a month to keep up with demand, easily.