Sunday, May 12, 2013

Gambling in Software

I want to tell you about a meeting we had a few days ago. It reminded me of “The Jack Story” (which was part of an old stage routine of Danny Thomas many years ago).

Here’s how it goes:
Traveling salesman gets stuck one night on a lonely country road with a flat tire and no jack. He starts walking toward a gas station about a mile away, and as he walks, he talks to himself. "How much can he charge me for a jack?" he wonders. "Fifty dollar, sounds reasonable. But it's the middle of the night, so maybe there's an after-hours fee. Probably another five dollars. Wait.... He'll probably figure I got no place else to go for the jack. Fifty dollars more."
He goes on walking and thinking, and the price and the anger keep rising. Finally, he gets to the gas station and is greeted cheerfully by the owner: "What can I do for you, sir?" But the salesman will have none of it. "You got the nerve to talk to me, you robber," he says. "You can take your stinkin' jack and shove it..."

The meeting was about a new feature requested by one of our customers. The feature was quite clear and we started talking about how we should implement it. At some point one of the participants claimed that if they need this feature they will surely need another related feature. A third guy immediately followed with: "if this is the case then we should also implement this feature…". This routine continued a few rounds until everybody were convinced that this feature was too big and should be rejected.

It seems that more often than one might think we follow 'The Jack Story" while building software. Fortunately, our story ends well. When we got back to the costumer and explained to him why we must reject the feature he stated that none of our guessing were true and he really only needs the original request. This time we got lucky. No extra work was done and we did not lose any costumers.

But it got me thinking. Did we do something wrong?

Now the typical agile practitioner would argue that we simply should not have added new requests on the original user story. Well...obviously my colleagues and I know this argument. We also know that the costumer often does not fully understand what he really needs. Moreover (perhaps not in this case) any company sometimes needs to be a head of the market instead of following it.
Actually, many times as software engineers we do more then we are explicitly requested (over doing). We enhance existing features. We build our code more generic and powerful than we currently need. We basically gamble on future needs, and I deliberately use the verb 'gamble' and not the verb 'guess' because there is a definite rewords for good bets. Naturally, 'Over Doing' also relates to a person character. Some will choose the 'Over Doing' approach more often than others. But everyone does it at some level.

Usually where ever there is a gamble there are measures and statistics. This must be done in order to track our gamble and measure the profit. This is also the case, for example, in software estimation which in essence also involves gambling. We continuously review our past estimation in order to improve our future ones. But this is not the case with 'Over Doing'. We never mark which of our work is mandatory for now and which is a gamble on a future need. As a direct result, we never come back to check if we were right.

So I answered myself: No, we did not do anything wrong. We should continue to gamble on future needs. But we also must find a way to document and review our gambling. It will enable us to estimate the profit of our gamble and help us improve future ones, avoid over engineering where it is not needed, and insist on generic code where we see future opportunities.



A key tool for a manager is matrices. We already know that traditional matrices in software engineering often provide little help for a project success. You can read about another matrices we suggested in Effective Unit Testing - Not All Code is Created Equal. In the agile era we are in a quest for finding new matrices. New things to measure which might help us navigate our project to safe shore. This post tries to suggest such alternative metric which might be useful.

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