Shelf Life Testing:  One of the most important discussions in the product creation stage relates to the shelf life of the product.  Retail buyers demand a certain minimum of shelf life for certain product types and categories.  Client brands can do shelf life testing themselves by placing product in a room temperature environment for a number of months (for shelf stable product) and observe how the product lasts.  We out-source shelf life testing to labs who are able to do speed testing as well.
Definition:  Shelf Life testing is a collection of analytical, chemical, microbiological and sensory testing. The objective of shelf life testing is to show how a product changes as it ages. Furthermore, provide information to help you set: use by/sell by/best by and expiration dates.
Source:  www.midwestlabs.com