that had a huge field sales force, all had company mobile phones. If one had an issue the SIM card was moved to a spare and the phone sent to the vendors repair centre for fixing. The company didn't even try to trouble shoot - just swap SIM, send staff out again, ship phone out to repair as per the contract. Dead simple. If all have their favourite phones that won't always be possible.

Another advantage of the corporate phone set up was they were all on the one account with a huge volume discount rate.