Wes and Craec , thanks for your idea and response. our products is pp chemical fiber which can be physically stable for a period of time , our customer request us to give them a quality ganrantee time , in this term , if any quality problem occured, they can make claims to us.
OUr previous method to define the term of shelflife is based on historical data , we have some goods had been stored in the warehouse for 1~2 years , we took samples from the stock , and re-test the product properties ,if it's within the spec. then we can determine the shelflife is 1~2year as we found no big change about the property. But the problem is if it's a new product , how we determine it ?
We considered to have a aging test , and thought about to make analysis of each rawmaterial , and get information from our supplier about shelf-life of the material , but think about this method, maybe 1+1 =/ 2?
Can you find solution for it ?
maggie