January 24, 2012

...Learn TDD with Codemanship

Jason's Handy Guide To Evaluating Software Packages

I get asked this question a lot, but it never occurred to me to write down my usual answer.

How do we evaulate shrink-wrapped software against our needs?

Well, that's easy. You still need to do the usual business requirements analysis. Identify who will be using this system, and what their goals will be for using it. In the good old days, we called these "Use Cases". Yep, even if you're buying and not building the software, you still need use cases.

The next step is to flesh out the design of your use cases, as we might normally do, by describing how the user interacts with the software to achieve their goal.

When we're describing software we haven't built yet, this is design. When we're describing how we'll use software that already exists, this is a process of validation. Can the user achieve their goal using the software we're evaluating?

Even with the most feature-rich packages, we tend to find we don't get an exact match. It's not always possible to achieve every user goal using the software. So as we validate the software against our use cases, we may identify gaps. There are almost always gaps.

The next question we need to answer is can we fill those gaps? Let's say we're evaluating Microsoft PowerPoint for our training business. It doesn't do everything we need out of the box. Let's pretend we have a use case where the trainer needs to populate a slide with an organisation chart showing the reporting structure of the group attending the course. She has a spreadsheet with those names listed in alphabetical order and with information about who reports to whom. using PowerPoint's built-in scripting language, Visual Basic for Applications (VBA), it is indeed possible to take that information and automatically generate an Org Chart.

So that gap could be plugged, with some work. Write a reminder about it down on a blank index card. This is now a potential "User Story" for some programming work that would need to be done if we went the PowerPoint route.

Of course, people identify gaps in software all the time, and it's possible that someone somewhere has already found a solution to plugging some of your gaps with handy tools and utilities. Google is your friend here: search for solutions before you think about reinventing the wheel. If you find one, and there's money involved, write down roughly how much on the index card.

Finally, don't forget the non-functional requirements. A package may offer the right features, but it may not be able to handle a high-enough volume of users, or it may not be secure enough for your purposes, or it may take a long time for users to learn. Evaluate thye software against these criteria, too. Be as explicit as you can. Handwavy requirements like "it must be scalable" aren't very helpful for validating software. What do you mean by "scalable" - a certain number of users at any one time, or a certain number of transactions per second, or the ability to run it on more servers?

All too often, businesses buy a solution and then validate that it does what they need - often by actually trying to roll it out. Whether buying or building, the key is to have clear, testable requirements and to validate the software against them. Don't be seduced by their sales patter and let them lead you like a donkey to the slaughter to their feature list. What their software does is far less important than what we can do with their software.

Posted 10 years, 7 months ago on January 24, 2012