DELAYED EXPONENTIAL CALLS SERVED IN RANDOM ORDER 375 



'^ p. 

 o 6 



'^ 4 



■ 0.001 



5.0 7.5 10.0 12.5 15.0 17.5 20.0 



t/h = DELAY IN MULTIPLES OF AVERAGE HOLDING TIME 



22.5 



Fig. 

 c = 6. 



13 — Delayed traffic served in random order, exponential holding times, 



To carry the 6.25 erlangs of traffic and meet the average delay require- 

 ment we see that 8 operators will be needed. Will 8 operators also fulfill 

 the no more than 20 per cent delay over 1 minute requirement? Enter 

 Fig. 14 (the c = 8 chart) with an occupancy of a = 6.25/8 = 0.78. The 

 per cent of calls exceeding a delay of 60/100 = 0.6 holding time is about 

 12 per cent. A provision of 8 operators satisfies both requirements. 



Table I 



