Your chances of survival are enhanced by having “stuff”. More stuff is often better. But what stuff do you have already, what stuff are you low on and is any of your stuff expired or nearly so? Having an inventory is a wise choice. This can be on paper, or a more versatile option is to use a computer database. I like the freeware “MUIbase” for its ease of use and power and support.
See the article here: http://survivallife.com/survival-databases/
Keep in mind that this is a PRE-SHTF solution. Lack of electricity or an EMP may make your list unavailable. So keep a backup on a USB protected from an EMP (in a “Faraday Cage”) and print out the list after major changes.