Tuesday, October 5, 2010

Commitment: what can we really commit to?

I want to discuss a foundational topic that influences the management of software development: commitment. In particular I’m looking at this from the perspective of a business that develops software not for sale, but as an enabler to their operations. As such a business we commit to customers that we can do things. That we can do them by a certain date. That we can do them to a certain level of service, or quality. These commitments cascade down as implicit obligations for the operational teams that conduct the sold work and those that support them.

Except…in reality, no matter how much we want it to be so, software development teams creating products can’t really commit at this level when we have no idea what promises are being made or complexities are involved.

I know. That sounds pretty bloody useless. But it’s true. And to think otherwise is naïve optimism that is just waiting for disappointment.

What we can commit to is releasing working software regularly. In fact, when you’re working to Scrum principles, at the end of any sprint the software should be “potentially releasable.” If you can handle it that often we’re ready to go.

In many businesses dates are already determined, and features are already determined. Given that resources (that is, the people available) are also largely determined (“no you can’t hire any more people, make do with what you’ve got”) it’s rather apparent that all three variables of software development are being fixed. (We’ll assume for now that the fourth variable, quality, is considered non-negotiable by the team developing software, i.e. they as professionals will not compromise quality as a response to the inability to negotiate dates, features and resources.)

Fixing all three like this can work with a great team and a bit of luck. However, given a bit of bad luck or changes in staff that inevitably occur over time and problems will likely arise. Whether we acknowledge this and try anyway, or wait until disaster ensues and then start investigating misses the point: this is not a reliable way to develop software.

There is a “better way”. This “better way” however requires a bit of a mind-shift for those used to the more traditional approach. At its heart is prioritization. This is where things can get difficult for people who are commissioning work. It’s natural to want to say “Hey I just want it all, and by March too, we’ve sold it so it’s basically promised. Just find a way to make it work.” For a business to allow people in this position to operate this way is, in my opinion, a little bit like the proverbial Ostrich burying its head in the sand.

Indulge me by considering the following contrived little story.
If a tap* can, when fully open, fill a 5 gallon** bucket in a minute then that is just a simple fact with which you have to contend. No amount of wishing it could do more will make it so.
Further consider: you have two buildings on fire, burning away, your garage and your house and that you’d like them to be put out. The firefighting team can deploy the water anywhere. Now ordinarily you wouldn’t get to influence what firefighters did. But imagine for a minute that you can. Further imagine that the garage contains a stash of priceless artworks, but that the house is empty. Left to their own devices, the firefighters would probably think they were doing the right thing by concentrating on the house. But YOU know better. Obviously you would have them put every last drop of available water into preserving the garage. You realize there isn’t enough water to tackle both burning buildings. You realize you can’t have them save both the priceless art and the house. You realize that demanding the firefighters save both buildings ain’t gonna happen. You prioritize, and save the art.
In other words, you have recognized that You need to decide how much water to put on which fire when, and you need to accept that you can only get 5 gallons every minute to distribute amongst them.

Once you’ve realized this is the way the tap works, and there isn’t anything you can do to make it spit out water faster then you’ve learned one of the most valuable truisms about software development. You can only do so much with limited resources. To make best use of them you need to prioritize how best to deploy them. And if you want to do more, you need more resources.

* or faucet if that’s your thing
** or, again, 18.92706 liters (or litres) if you must – as you can see I’m conflicted and inconsistent with both terminology for everyday items and units of measure after living in the US for 8+ years

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