Automation - The Practice of Cloud System Administration - page 243

• Tasks classified as rare/difficult should be documented and tools should be created
to assist the process. Documentation and better tools will make it easier to do the
tasks correctly and consistently. This quadrant includes troubleshooting and recov-
ery tasks that cannot be automated. However, good documentation can assist the
process and good tools can remove the burden of repetition or human error.
• Tasks classified as frequent/easy should be automated. The return on investment is
obvious. Interestingly enough, once something is documented, it becomes easier to
do, thus sliding it toward this quadrant.
• Tasks classified as frequent/difficult should be automated, but it may be best to ac-
quire that automation rather than write it yourself. Purchasing commercial soft-
ware or using free or open source projects leverages the skills and knowledge of
hundreds or thousands of other people.
Withthisprinciple,theaimistoachieveefficiencybyautomatingeverythingthatitisfeas-
ible to automate. The human component is not explicitly considered. However, it is easy
to describe and reasonably easy to decide what to automate. Some of the lessons learned
using this approach can be applied even if this is not the only principle considered. In par-
ticular, considering tasks on the easy-difficult and rare-frequent axes is a useful tool for
those looking into automation.
12.1.2 The Compensatory Principle
Thecompensatory principle isbasedonFitts'slist,namedafterFitts ( 1951 ),whoproposed
asetofattributestousewhendecidingwhattoautomate.Theattributesareshownin Table
12.1 . Despitethemorethan60yearsthathavepassedsinceFittsperformedhiswork,these
attributes still apply reasonably well.