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Unit 11: Queuing Theory




          The expected number of customers in the system is given by,                           Notes
                                              
                                   L  =     =        
                                    s
                                              
                                               
                                                                                  (2)
                                              
          The expected number of customers in the queue is given by,

                                         
                                             
                                         
                                               
                                             
                                               
                                                 
                                                                                  (3)
                                                
          With an average arrival rate , the average time between the arrivals is 1/. Therefore, the mean
          waiting time  in queue,  w  is the product of the average time  between the arrivals and  the
                               q
          average queue length,

                                             
                                  W =                                           (4)
                                    q          
                                             
                                     =       
                                                
                                     
          Substituting                        
                                    
          Similarly the average waiting time in the system,

                                             
                                  W  =                                          (5)
                                    s          
          putting                  L  = l (m - l),
                                    s

          we get                  W  =
                                    s    
          Queuing Equations

          The evaluation of Model I is listed below:
          1.   Expected number of customers in the system:

                           
                        
                          
          2.   Expected number of customers in the queue:
                              
                           
                            






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