Editing Computer-aided dispatch (section)

===Concentration===
CAD systems require support staff with special skills. This can lead to concentration of dispatch facilities, particularly where there is population growth or where automation is required to meet defined service objectives. 

In any system, concentration of facilities increases risks of outages or massive failures. In a system where the call traffic is so high that advanced technology is needed to handle routine levels of day-to-day calls, relatively minor failures can have major effects on service levels. For example, where everyone is used to the convenience of automatic vehicle location (AVL), an AVL outage can suddenly increase staff workloads. Suppose a failure causes a condition where CAD cannot recommend a closest unit. How will the dispatcher efficiently assess which unit to assign?