I used to use a hedonic scoring system (aka organoleptic testing) coupled with shelf life analysis in the meat industry, though it may vary depending on the risk of your product (I'm going to have a stab in the dark and guess you are in the chicken industry!). There is quite a good pdf available called "Shelf Life Testing: Procedures and Prediction Methods for Frozen Foods" by Bin Fu on the internet that gives fairly substantial scientific back-up if you want to go to town on this topic altogether, but as long as you/your quality team/customers are happy with the texture/flavour/appearance of the product after 9 months, you can prove you are controlling the freezing process and you can prove bacterial growth will not occur in the product, you should be fine.
One word of warning though, fully expect your production manager to repeatedly ask the freezer man to throw out your retained samples. This is most likely to be at the 8 month mark!
