You will be regulated by whatever company you work for's SOP's.
Don't dismiss it as an idea too quickly though. Most companies accept this method and if you also have an inventory with it, when you change companies it won't be too much effort to comply with the new COP's.
Foam cutouts on line is a brilliant idea as when your busting your nuts to get a plane out during an AOG, the last thing you want to be doing is trying to count your tools before releasing an already late aircraft full of passengers. To be able to do a quick scan of your tools and instantly see one missing is invaluable.
If your in the hangar then you generally will have a roll cab with plenty of space.
The Military generally mandate this as tool control.
I use a Pelican Case. Works a treat and also takes the knocks on flying spanner duties.