Queuing is a common sight in the service industry such as bank transactions of employees receiving their wages at the end of a fortnight and other customers working in private or sector. Customers and service providers place differing values of the time. Those who have access to privileges with...

Previous emergency service covering models consider all the calls to be of the same importance and impose the same waiting time constraints independently of the service's priority. This type of constraint is clearly inappropriate in many contexts. For example, in urban medical emergency...