Joseph Hinkle at MyITForum.com

One of the most difficult things a person can ever do is prove that a company should buy something that "everyone knows" that they need. When everyone knows, it seems that no one can prove that it is a good idea. Often, it is hard to quantify very obvious benefits, like better visibility to current state for planning purposes. Usually, especially for large purchases, an ROI calculator will be used to compute the return on investment and help quantify those intangible benefits.

I spent a couple of hours today, with a group of people, plugging numbers into an ROI calculator for a project that we're working on. It was an interesting exercise that left us all feeling that we weren't any closer to making any determinations. A big problem that we had was that we didn't believe the numbers that were coming out of it. Any research organization - Gartner, Forrester, and the like - bases the calculation on the research that they have done. That's great, but an average is just that. Depending on the industry, a company could be well above or below the average.

That wasn't our biggest problem though. That was figuring out what our numbers should be. Imagine a scenario where you are tasked with figuring out how many devices you have. You need to know this number to justify buying SMS. How do you do it? You don't have a mechanism for discovering these devices, so you will probably go back to purchasing data. What if your purchasing system is hard to extract data from? In the end, you make a guess and hope it is close to correct. Imagine doing this for a large number of fields in a spreadsheet that will do calculations based on your guesses. At the end, you might as well just make up a number.

In the end, my advice is this. Spend the time. Don't set aside two hours to make those determinations. Don't wait until the last minute to start building your justifications. If you do, you might have all the time you could ever want after the project gets canceled. Return on investment is a key part of any business case. It has to be a number that is both believable and defendable. If you don't believe in the number, no one else will either.