I have been doing similar things all my life too. I have found that the best place to start is with a problem. For example, we have a huge site that is armed by a security guard. Before he can arm the site he has to walk through each building to make sure that no-one is still working before he arms it, the problem is some of these buildings are so big that by the time he has walked through from entrance A to entrance B someone has come in from entrance A and is sat at their desk working when the guard is setting the alarm. The site has access control and there are time restrictions on peoples cards but they need the access to work in order to get out of the building. We could just restrict their cards not to work on the external doors after working hours, but there are many nights when the building is open and staff will require access after hours. So there was no easy way to restrict staff from coming back in. Our solution was a lock down fob, the guard now has a red fob that he swipes at the entrance a when he comes round to lock up, this disables all the external readers but not the internal ones so staff can get out. Only red fobs will now work at the external doors. The red fobs also work at the alarm keypad and so once he has checked the building and got everyone out he swipes the red fob at the alarm which arms the system. Only people with a red fob are able to enter the building (they are keyholders) and when the alarm is unset it automatically resets the access control so staff can get in.