The Value of Unit Testing

Question

Here are some typical answers(ranked in ascending order of corniness) I get from managers/bosses whenever I bring up the importance of having unit tests and code coverage as

Answer 1

Why don't you just write unit tests for your code? Do you know if there are some other developers having the same problem? Probably they will follow your example and write unit tests, too.

I don't think that the problem is the technique or the costs for an integration server. The problem is the management's attitude to unit testing. So convince them with all developers.

There are lots of hints in this thread (Jon Limjap's answer), try it!

Answer 2

People listen to their wallets. Show how much time you can save by catching bugs early on. Translate that to dollar-savings.

Answer 3

Most managers won't see the advantages of unit testing until they see it in action where it makes sense, so my advice, based on experience, is to take the ff steps:

1. Apply unit tests to recurring bugs - This is the best use case to prove the value of unit tests. When you have bugs that just appear and reappear every other build, the unit test will allow developers to see which changes caused the bugs, aside from alerting them in advance that a fix is in order. It's quite easy to demonstrate to management as well.
2. Apply unit tests to regular bugs - With the usefulness of unit tests now clearly demonstrated, several instances of recurring bugs disappearing in the long term should be enough to encourage everyone to use unit tests to evaluate all bugs, to prevent them from becoming recurring bugs.
3. Apply unit tests to new functionality - With unit tests making sure that old bugs don't reccur, and confirm that they are fixed in the first place, the next step would be to apply it to new functionality to ensure that bugs will be minimized. Make it clear that it is impossible to totally eliminate bugs.
4. Apply full blown TDD - The final step will be to apply unit testing even before coding, as a design tool that both helps in designing code and minimizing bugs.

Of course I'm not saying that this is easy -- what I had stated above is an oversimplification which even I struggle with everyday -- it's difficult to convince everyone.

If later you decide to move on to a different company, you may want to explicitly look for a company that practices TDD.

Answer 4

One other thought to add to the other excellent comments on this thread (many of which I've upvoted): make sure that your management knows that Unit testing is very highly automated at this point. I find it very impressive to pop NUnit on the screen, hit the "Run All" button and see dozens of green-lighted tests being passed in seconds. Do that once, saying "this verifies that all of my older work is still correct despite all of my newer changes" and you just may win a few converts. In any event, they'll come to trust you - with your visible proof of quality - more than they trust others. That can only be good for your career.

Answer 5

With regard to #3, spending time on unit testing will most likely decrease overall time to market. Great article - http://blog.scottbellware.com/2008/12/does-test-driven-development-speed-up.html

Answer 6

Well the classical response is that the earlier you catch a bug the less expensive it is to fix, I think most managers can relate to that.

As Mark said showing something concrete is the best way to convince PHBs that something is good as they are so used to hearing talk and probably don't know the difference between unit testing and other testing.