workload simplified

[Fred Sturm]

Rather than weigh in on the current discussion, I think it would be
more fruitful if I explained the current workload formula in a bit of
detail. It's obvious from some of the comments I have read both on list
and privately that a large number of cauts don't really understand how
it works, and find it rather forbidding. I should probably have done
this last fall, but there's no time like the present. (Actually, there's
no time _but_ the present, but I'd better not get into that).
	The formula begins with a base workload constant. In the current
Guidelines (which I will refer to as 1990 version), this number is 60.
In the proposed draft (2002 version), there is a choice of 40, 60, 80,
or 100. These are not arbitrary numbers. Rather, they are based on the
experiences of a large number of technicians over a period of decades.
There is a broad consensus that workloads in this range allow for
comprehensive maintenance of pianos in institutional settings over the
long haul. 
	The surveying I did last year (which didn't produce adequate responses
to produce what I was after at the time - a supplementary document
showing some real life numbers at real institutions; I haven't given up
on the idea, but it's on hold) reinforced the idea that these numbers
are good ones. Nobody with a workload over 100 thought the pianos were
being taken care of adequately. And within the range of 40 - 100 there
were examples of technicians who did think they were able to do an
adequate job under their particular circumstances. 
	I should note that the text of the 1990 version refers to workloads
between 40 and 80, and it is only in the workload formula that the
number 60 is adhered to. There is no reason 40 or 80 couldn't be plugged
into the 1990 formula.
	This is fine as far as it goes, but we all know that there are many
variables which make circumstances enormously different from one
another. Exquisite climate control versus 70% plus swings; a brand new
inventory versus a 75 year old one; moderate use versus places where 16
plus hours hard playing per day is the norm. In other words, there are a
number of factors that increase or decrease the need for work, and they
have been pretty well identified in the 1990 formula (though there are
several quibbles with wording).
	So the idea is to assign numbers to each factor which, multiplied by
the constant, will predict a reasonable workload under varied
circumstances. Let me take one factor in isolation to show how this
works. I'll choose humidity (climate control).
	1990 version:
(1.00) Excellent: 10 percent maximum variance in relative humidity. 
(0.90) Good: 20 percent maximum variance in relative humidity. 
(0.80) Fair: 30 percent maximum variance in relative humidity. 
(0.70) Poor: 40 percent maximum variance in relative humidity. 
	The first important thing to note here is which choice has the number
one next to it (1.00, excellent). The basic assumption under the 1990
version is that humidity must be controlled within 10% for the basic
workload to hold. Any greater variability will increase the workload. (1
x 60 = 60).
	The second thing to note is how much increase is workload is assumed
for an increase in humidity variability. To take the extreme, it is
assumed that a 40% variance will allow a technician to take care of .70
as many pianos (70% if you prefer), or, using the 60 base, 42 pianos
(0.7 x 60 = 42). [Apparently conditions with variance in excess of 40%
are unheard of <g>.]
	2002 version:
1.3 - Excellent: 15% maximum variance in relative humidity (or has
humidity control unit installed and well-maintained)
1.0 - Good: 30% maximum variance in relative humidity.
0.7 - Fair: 50% maximum variance in relative humidity
0.4 - Poor: Greater than 50% maximum variance in relative humidity
	Note again where the one (1.0) is: this time at "Good, 30% variance."
In other words, this formula assumes that the base workload works at
institutions with 30% variance, and that it might be possible to have a
larger workload if humidity were controlled more tightly. How much does
this factor influence the workload as predicted by these numbers? Again,
to take the extremes, and using the same 60 as base, it predicts that,
for 15% maximum variance, one tech could manage 1.3 x 60 pianos (78),
while with greater than 50% variance, it predicts a tech could manage
only 0.4 x 60 (24) pianos. 
	In asking for feedback, I am asking whether these numbers are at least
close to reasonable. Are the percentages good ones? Should there perhaps
be more (eg, 10%, 25%, 40%, 55%, greater than 55%)? Are the multipliers
reasonable predictors of how much humidity variance affects workload?
(To compare, the 2002 version has a difference of over 3 to 1 between
excellent and poor, while the 1990 version has a difference of only 1.4
to 1).
	This is pretty long, so I'll stop here. I'll come back at you with the
other factors at decent intervals.
Regards,
Fred Sturm
University of New Mexico