Page 165 -

W h a t Y o u C a n D oh a t Y o u C a n D o
P
136 P a r t I I I : a r t I I I : W
136
• Technological life A system may become impractical to maintain even though it
can still be repaired and maintained. For example, it might not be possible to find
the right type of memory chips for the system because they are no longer made.
Another way to look at this is obsolescence.
• Economic life A system might still be functional, but it costs too much to use. It
might also be that newer systems can be purchased that have lower operating costs
so that the payback period of making that purchase is short.

Months 6 12 18 24 30 36 42 48

Useful Life

Economic Life

Technological Life
A system’s life is based on economic
and technological factors.

It might not be possible to precisely predict the lifetime of a system up front, but you
can estimate it by taking these factors into consideration.

Cost
Of course, overall cost is an important factor when evaluating your system’s life cycle. But if
you find a computer that costs US$2000 to buy, realize that you aren’t just spending $2000
per box. You also have to pay for the electricity to power it. You also have to consider
maintenance costs, and the like. So when figuring out cost, you must include a number
of factors:

• Initial purchase price The typical balance IT managers face here is deciding whether
to pay a higher upfront purchase price in the hope that lower operating costs can be
realized. There are also issues of how much money can be spent on the upfront
purchase price.
• Energy costs The power it takes to run your machines can be a significant part of
overall costs. The more “high performance” a computer is, the more likely it will
need additional cooling, which also adds to the overall power cost.
• Maintenance If you buy especially inexpensive computers, you may find yourself
paying more in maintenance costs. Cheap computers are great at first, but when
hard drives fail and NICs don’t work properly, you’ll spend money fixing these
computers.