ECONOMICS OF TELEPHONE RELAY APPLICATIONS 237 



The worth of the time taken for the <i,roup as a whole is then 



Cji/ = Ctt/p = Ctat^/p = Cibts/p = etc., dollars. 



The y-dhie per event is usually of principal interest. Since there are 

 (a -]- b -\- c -\- ■ ■ •) events in any one ''major event," then the total 

 value per event Ce is 



C 



Ce = 7 — I — 1_ — p- — , ^ dollars per event, 



CttA , for path A, 



CiIb , for path B, 

 (a + 6 + c + ■■■)p 



= etc. 



Then the value of an event, per millisecond, is 



Ce = QACt/p = qsCt/p = etc., dollars per event per millisecond. 



.a b 

 where Qa = — —r—, , , Qb = — — r— j ■ , etc. 



In general, then, the value of an event is ^ 

 Ce = CeIe dollars, 

 where Ie = the duration of the event, 



Ce = \~]ci dollars per millisecond. (19) 



\P/ 



The quantity q will be called the "path factor." It is seen to simplify to 

 a value of unity when a major event is involved, (q = a/ a), and in all 

 other cases to have a value less than this. 



1 .42 The Value of Speed, per Relay Operation 



Each e\'ent may consist of the action of one relay out of several possi- 

 l)le alternates. This means that several relays must be purchased for 

 each such event, though only one determines the time. Caliiiis ir the 

 number of relays provided per marker to perform one function, each 

 function being designated by sul)script corresponding to path and se- 



