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THE BELL SYSTEM TECHNICAL JOURNAL, JANUARY 1954 



within the marker which directly affects its working time, referred to as 

 a "major event." 



1.41 The Value of Speed per Event 



Within each major event there may be a whole cycle of operations 

 happening partly in parallel and parth^ in sequence. Each separate ac- 

 tion is called an '"event." In the case of events happening in parallel, 

 the circuit designer will usually know whenever one path is in outstand- 

 ing control of the work time as a whole. Whenever such is the case, it is 

 a "major event," and the other paths may be ignored. Often, however, 

 the times for each of several paths will be about the same, and special 

 consideration is needed to determine their value. In breaking down these 

 operations so as to arrive at the cost per relay, one must evaluate the 

 events within any major event as in the region marked in Fig. 8. Suppos- 

 ing that the number of subevents within a major event are labelled a, 6, c, 

 etc. for each of the several parallel paths, then the total number of 

 subevents isa+6 + c + d+---. The total time for the major event 

 is t, which has the dollar value, Ct/p, per millisecond, as just previously 

 given. 



Along any path. A, of events, the total time for the events is the time 

 taken by the group as a whole. If this total time is t, then the effective 

 time per event along any path is 



Ia ^ t/a for path A (seconds), 

 Ib = t/h for path B (seconds), 

 = etc. 



PATH A: a EVENTS 



PATH B: b EVENTS 

 X -X 



-PATH C: C EVENTS 



-X — -x -X- 



PATH D: d EVENTS 



-X X X- 



-X X ^x- 



Fig. 8 — Typical chain of events in controller operation. 



