Software Design, or the lack thereof….

November 6th, 2007
[ Software Development ]

“Generally the last thing you should do when beginning to design an interactive system is write code”, Bill Buxton.

I can’t really argue with Bill on this one. Unfortunately it flies in the face of agile methods which suggest that you write code as soon as possible. While I’m a fan of what agile methods strive to achieve, generally I see more cons than pros in practice.

Just to confuse myself, I’m about to completely contradict myself. Here’s why you should write code early, and it has nothing to do with the quality of experience of the resulting product, it’s about everything else. What else is there? There’s your team and getting them to work together, getting them up to speed on the problem domain you’re working in. There’s the technical bits like setting up source code control, issue trackers, development and qa servers. There’s the actual act of building and deploying a piece of working software.

All these are non-trivial bits that have very little to do with the quality of the experience the software delivers. You can deliver on all these and still end up with useless products. They are, however, real reasons why you want to deliver working software as early in the process as possible. To be honest, what you deliver in these early stages is almost irrelevant. It’s about getting the team and tools in place and working together. Think of it as training camp in sports.

Now for the contradiction. Writing code as a means of design is an expensive way to design poor software. It’s a great way to build a development team but clearly there’s a required balance here. Software is about the only industry that prototypes almost immediately. Look at architecture and automobiles as an example (Before we take this too far, I’m not suggesting we simply copy those industries). In both those more mature fields, they involve lengthy design phases prior to prototyping. As Bill mentioned in his recent talk, every automobile built today first had a full scale clay model rendered at costs of upwards of $250,000. The key being that they don’t get the clay out on day one. They spend months researching and designing long before they move to the prototype.

This isn’t a power play. This isn’t about removing software developers from the design process. This isn’t about no longer allowing the software construction process to inform and influence design. This is about building software that delivers a better and more relevant experience to the end user. This is about respecting and making effective use of one of your most valuable ‘tools’, your software development team. Yes, I just called myself a tool.