Hi Yeeling,
One popular option to assist yr query is ASLT – Accelerated Shelf-Life Testing.
This methodology involves -
(1) a decision as to what specific variable(s) and their associated values determine the existing shelf life, eg whether safety /quality related, such as (a) being dependent on microbial pathogens or (b) taste, appearance.
(2) If safety criteria are controlling shelf-life, regulatory factors may be involved; if quality criteria are controlling, the relationship between the variable(s) in (1) and temperature are investigated at various elevated levels which enables an estimation of the shelf life at the current storage temperature.
Hopefully you know how the current shelf life was established which should answer (1,2) as to the possible choices. If yr product is ambient shelf-stable, I anticipate the shelf-life is quality related.
PS - Welcome to the Forum ! 