Xref: utzoo news.sysadmin:2293 comp.misc:5810
Path: utzoo!dptcdc!jarvis.csri.toronto.edu!mailrus!ames!elroy!cit-vax!mangler
From: mangler@cit-vax.Caltech.Edu (Don Speck)
Newsgroups: news.sysadmin,comp.misc
Subject: Re: computer charge back
Summary: single rate is suboptimal
Message-ID: <10393@cit-vax.Caltech.Edu>
Date: 17 Apr 89 02:27:31 GMT
References: <885@hawkmoon.MN.ORG> <1989Apr16.020150.1083@utzoo.uucp> <16570@oberon.USC.EDU>
Organization: California Institute of Technology
Lines: 29

In article <885@hawkmoon.MN.ORG>, det@hawkmoon.MN.ORG (Derek E. Terveer)
asks what rates to charge on their Sun workstations to recover costs.

For consumables (such as paper), charge what the consumable costs.

However, computers are mostly fixed costs, independent of utilization.

For those resources that somebody has to themselves all the time, such
as a personal workstation or terminal in an office, or a disk dedicated
to one project/account, charge a flat rent (reflecting the fixed cost
of this dedicated resource).  Administrators often like this, since
then their costs are not subject to the whims of users who typically
never see the bills.  It also means that nobody gets yelled at for
soaking up idle cycles.  (If they want to resell the idle cycles,
let them).

For pooled resources, such as public terminals/PC's, terminal-switch
ports, public disks, and timesharing CPU time, where increasing the
supply entails permanent cost increases, charge a usage rate proportional
to  the demand (high when demand is high, cheap or free when there's
plenty to spare).  If it's prioritizable, like CPU or printer scheduling,
charge by priority.  The idea is to discourage overcrowding but
encourage utilization so that average rates stay low.

CPU time should not carry a usage charge unless the CPU is timeshared
with other users (typically not the case on PC's and workstations).

Don't charge for connect time on pty's when you can create more pty's
very cheaply.