I think everyone here can't get over the 50% goal. Who decided that?
Every Chef uses diferent tools to manage costs. With 85% frozen/packaged stuff, your labour is at an absolute minimum, but costs are high. Then again, if you're operating a chain restauarant, you HAVE to use the pre-determined products and the pre-determined suppliers.
So, you need to have the big, big, picture. You're daily sales fluctuate, why? Did the chain put out advertising that week? Was there a huge event in town? Can you forecast a spike in sales? This is where you really have to work cloesly with f.o.h.
If you can establish par-levels for days of the week and enforce them, you can get a handle on wastage.
Twice-weekly deliveries instead of weekly deliveries. Of course the purveyor will fight tooth and nail over this one.
Like tincook says, put locks on the fridges if theft is a problem.
Who's ordering food? How well does that person understand the purveyor's pricing system and general B.S.?. Suppliers have a zillion ways to pad an order, and with chains its just so much easier.
Like I said, if you could magically get food cost by 50%, my first reaction as an owner would be to dig up the old Chef/kitchen manager and have him arrested for theft.
Of course, the opposite side of the coin is more volume. More volume = more sales, which usually means better food and labour costs
Do a lot of your planning on paper. If you can show the powers-that-be that IF you had some freedom with suppliers, you could bring down the foodcost by 4 or 5 percent--show them the prices for, say frenchfries (chips?) from supplier A B, and C, fryer oil, burger patties, etc. Shpw them on paper that IF you bought in frozen raw burger buns and proofed and baked them on-site, the costs for that would be almost 8% cheaper, with no more stale buns.
Don't know if this helps