These models have been  developed to establish a trade off between  costs of  providing and the waiting time of a customer in the queuing system. Constructing  a model entails describing the components of the system arrival process queue structure and service process and solving for the measure of performance average length  of waiting  time  average time spent by the customer in the line traffic intensity etc of the waiting  systems.
Competitive Models: These models  are used  to characterize the behaviour of  two or more opponents ( called players) who  compete for the achievement of conflicting goals.  These  models are classified according to  several factors such as number of competitors sum of  loss and gain and type of strategy which would  yield him the best  or the worst out comes.