Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!telxon!mikem
From: mikem@telxon.UUCP (Michael Molnar)
Newsgroups: comp.windows.x
Subject: Ergonomics of X-Terminals
Message-ID: <554@telxon.UUCP>
Date: 30 Oct 90 15:15:26 GMT
Reply-To: mikem@telxon.UUCP (Michael Molnar)
Distribution: na
Organization: TELXON Corporation, Akron, Ohio
Lines: 144

Our department was seeking justification for converting standard ASCII
terminal (GraphOn 230's) over to NCD X-Terminals.  Well, the gnashing of
teeth is over, upper management is convinced that we need them and the
check is as good as in the mail.  

But the justification did not come easy.  In this three part article I
document the saga of trials and tribulations.  

This is part 3.  The conclusion of a three part series on "Ergonomics
of X terminals".   In the previous parts, I presented the replies from
other X users, and the qualitative arguments which our group presented
to management.

But management was still not convinced.  They wanted real reasons. 
Spell that $$$$.   So here is how our group replied ....

(For commercial reasons, the actual $$$ for Burden rate and cost of X
terminals can not be presented.)

X-window savings for User Support.
(Our group has two major purposes, to write tools for Corporate
use and to support those tools.)

Types of support sessions
1.  consultation - answering user question requiring only viewing
    data on system.
2.  system help - solving system problem for user requiring modification
    of data.

Support time using Ascii terminal  (The below times are for one person.)

Session Type   	Number of   Time spent	  Time spent returning  	Total 
		sessions    with user	  to previous work	        Time
		per day	    per session	  per session		      per day
			    (minutes)	  (minutes)		    (minutes)
-----------------------------------------------------------------------------
Consultation	  3	      5.0 	 	  2.5 			 22.5
-----------------------------------------------------------------------------
System Help	  4	     10.0 	 	  5.0 			 60.0  
-----------------------------------------------------------------------------
Total		  7	      7.86 	 	  3.92 	 		 82.5



Support Time Using X-window Terminal

Session Type   	Number of     Time spent	Time spent returning  Total 
		sessions      with user	        to previous work      Time
		per day	      per session	per session	      per day
			      (minutes)	        (minutes)	      (minutes)
------------------------------------------------------------------------------
Consultation	  3		  3.0 	 	  0.0 		 	  9.0  
------------------------------------------------------------------------------
System Help	  4		  8.0 	 	  0.0 		         32.0  
------------------------------------------------------------------------------
Total		  7		  5.86 	 	  0.0 			 41.0  

Support Time Savings

Session Type		Ascii		X-window	Time Savings per Day
-----------------------------------------------------------------------------
Consultation Time 	 22.5		  9.0		 	13.5
(minutes)
-----------------------------------------------------------------------------
System Help Time	 60.0		 32.0		 	28.0
(minutes)
-----------------------------------------------------------------------------
Total Time 	 	82.5		 41.0		 	41.5
(minutes)


User Time - time costs for user requesting support

			Ascii		X-window	Time Savings 
-------------------------------------------------------------------------------
Average Time	
Per Session		 7.86		  5.86		    2.00
(minutes)
-------------------------------------------------------------------------------
Number of
sessions 
per Day			 7		  7		    7
(minutes)
-------------------------------------------------------------------------------
Total Time per Day     55.02		 41.02		   14.00
(minutes)



IR Programmer Time  - conservative depiction from engineer's impression

		Number of	
		context		Time to     Time to      Time to      Total   
		Switch    	Switch      Switch       Switch       Time    
		cycles		to editor   to compiler  to test      per day
		per day		(minutes)   (minutes)	 (minutes)    (minutes)
-------------------------------------------------------------------------------
Ascii		  12		  1.0 	      1.0	   1.0	       36.0
-------------------------------------------------------------------------------
X-window	  12		  0.0	      0.0	   0.0	        0.0
-------------------------------------------------------------------------------
Total Savings      0		  1.0	      1.0	   1.0	       36.0


Since the person both (1) offers support and (2) programs, the total savings
per day (minutes) is

	Support			41.5
	User time		14.0
	Programming time	36.0
	----------------------------
	Total			91.5

	Conservative effective
	Work Ratio		70%
	
	----------------------------
	Real time savings per
	Day 			64.0  minutes

	Real time savings per
	week			5.33  hours

	Real time savings per
	month		       22.24  hours


	Actual savings per month  =  time savings per month  x  Burden Rate
	     ($$/month)                    (hours)                ($/hr)

	Cost of NCD X-terminal = NCD

	Pay-Back Period  =  NCD  /  Actual Savings per month
	  (months)          ($)       ($$/month)


The bottom line was management was convinced that X-terminals would be
a wise capital acquisition.

-- 
Mike Molnar		|  uunet!telxon!mikem	   |    (216) 666-4300
TELXON Corporation	|-----------------------------------------------------
91 Springside Drive	|  "No, mom and dad, don't touch that!  It's evil!"
Akron, OH 44313		|             -- Time Bandits