My wife's former job was civilian US Army helicopter support. One ongoing problem was that tools went missing all the time. To ensure the right tools were used, they were supplied to the mechanics, who had lessened motive to keep track of them. There were repeated efforts to make tool-box inserts with individual recesses for the tools so an inventory at a glance could be done, but it always worked out that there was too much variety and therefore too much cost to manufacture them. So they tried to find a pour-in liquid that would either cool or cure. The best one was a promising proposal that went really well into a number of presentations, until the supplier mentioned that the fumes produced during the process were highly toxic. Yup - no one was going to ship this to thousands of Army mechanics to apply on their own.
The main loss of tools seemed to be simple theft, but you cannot necessarily be sure the mechanic missing the tool is the one stealing the tool.
As a side note, when moving helicopters by ship, they would frequently arrive with various knobs missing from control panels. The initial user claim was that shipping vibration was responsible, but they did some cases with full stretch wrap of the entire helicopter. I guess plastic wrap magically damped those high levels of vibration on the ships because the knobs of those helicopters arrived in place and secure. Sigh.