2.4 Operating Characteristics: Multiple-Server Model Let 1 = the arrival rate for the system; 1x = the service rate for each server; d = the number of servers. 3 Then 1 . * 4-4 (21 probability of no units in the system 7P (1/2) (k-1)(x - 2)2" Ll+ L average number of units in the waiting line average number of units in the system average time a unit spends in the waiting line average time a unit spends in the system We WW, ka - - )* (****) Po probability that arriving unit has to wait for service Probability of units in the system: for nk P = PO n! P. (1/2) PO A!) for n > 2.4 Operating Characteristics: Multiple-Server Model Let 1 = the arrival rate for the system; 1x = the service rate for each server; d = the number of servers. 3 Then 1 . * 4-4 (21 probability of no units in the system 7P (1/2) (k-1)(x - 2)2" Ll+ L average number of units in the waiting line average number of units in the system average time a unit spends in the waiting line average time a unit spends in the system We WW, ka - - )* (****) Po probability that arriving unit has to wait for service Probability of units in the system: for nk P = PO n! P. (1/2) PO A!) for n >