TCO (Total Cost of Ownership) has been the in-vogue way for some time now to "objectively" compare the services and applications and the engines and/or operating platforms that host them. If you don't know about TCO then the basic idea is this. Server A costs $15,000 in up front hardware and software fees and then costs $250 a month in maintainence time. Server B costs $5000 in up-front hardware and software costs and then $500 a month in maintainence. So over a 4 year period the TCO for the two servers is as follows.
So what the TCO interestingly shows that while Server A has a higher upfront cost (3 times of server B) the total cost when all is said in done is actually lower for Server A then Server B over that four year span.
Seems interesting right? Problem is there are many flaws in TCO comparisons, some obvious and some not. Here are some problems I have with using TCO for comparison.
Difference in time spans
In the example above I arbitrarily chose to use a four year life span but the results are of course very different depending on the span of time one chooses. If you choose a 3 year cycle then Server A is actually the better investment and if you choose a 5 year or longer cycle then Server B increasingly becomes a better choice.
It would be nice of course to see TCO's standardized to all use either (or both) 5 and 10 year cycles because realistically in deployment terms most servers will see a usage somewhere in that range. Until then however as a discerning reader you have to make sure when comparing TCO's that you are comparing equal lengths of time and ideally lengths of time that are equal to the length of time you will be deploying the server or platform in general.
Unrealistic and/or unfair maintainence costs
Totalling up up-front and ongoing costs is a deceptively simple excercise because while up-front costs can be calculated to the penny, calculating ongoing costs relies on estimates, guesswork and assumptions and in the end just isn't as accurate.
There are three pitfalls in guesstimating ongoing maintainence costs that as purchaser you need to be aware of when comparing TCO.
The reality is that TCO numbers like other "hard" numbers come through the marketing spin cycle much softer than they started. While anecdotal evidence does not normally outweigh that of hard facts when the "facts" themselves are squishy to begin with anecdotal evidence should be added to the mix to try and get a better understanding of what the TCO for a particular product is.
Am I suggesting that people or companies are lying? No. What I am suggesting is that you have to recognize that what is being presented is a version of truth that best co-incides with the goals of the company or persons presenting it. As an example Microsoft often uses low TCO compared to Linux as a selling point for it's higher end enterprisey operating systems. In my own experience for example there is no question that while Microsoft OSes require far, far less training and experience for most administration requirements as opposed to equivalently functioning Linux based systems I know of several Linux based servers that have been rebooted two or three times over a span of 3 to 5 years whereas the Windows based servers that I am aware of usually require rebooting on at least a monthly basis. While my own personal experience is just that, a personal experience, it is interesting to me to note that depending on which version of truth you want to use it either supports or contradicts the idea of a lower TCO for Windows.
|© 2008 Max Stocker|