I have several different "kits" that have always been configured in a modular format, with each kit self-contained for the most part. The two significant drawbacks to this method is that it is considerably more expensive since I often purchase several of the same item so that each kit is stand-alone, and of course the additional space and weight penality due to this redundancy when I carry several different modules.

I maintain an Excel document in order to keep track of everything. The file starts out with my basic EDC items, and then lists each individual module, all the way up to several large backpacks and an expedition level FAK that would be what I would throw in the car if I were planning to leave the house and never return.

There are several (a dozen or so) different worksheets, as each "kit" has its own dedicated section that is made up of several different "modules". At last count the main page (the first worksheet) is now well over 2,700 lines. The other worksheets that follow are considerably smaller, as they only list the individual items that make up the various modules that comprise that particular kit (i.e., Wilderness Survival Kit, Urban Survival Kit, FAK, Vehicle Kit, Camping Kit, etc.).

I generally try to keep a current contents list (printed directly from the Excel worksheet) within each kit, although it seems that I am constantly revising one or two items which renders the whole list obsolete. The other PITA with doing things this way is that if I revise a single item in a particular module, I then need to manually update each of the following worksheets that contain that module.

It's amazing how much time and money actually gets sucked into this "hobby" if you aren't careful.

Jim