I’m going to write a bit about my thinking process whenever I build things, whether it’s websites, VBA applications, or financial models. I’m not too sure if this is going to be a “oh that’s so obvious why is he telling me this?” piece, but if there’s one thing I’ve learned, one person’s normal behaviour may be another person’s exceptional one.
And I know you’re exceptional. So let’s get on with it.
My thinking process whenever I’m making things people use (i.e. goes into production) goes like this:
First, I ask myself (or the project champion/sponsor/requester): is this a one-off, or will there be many iterations?
If it’s a one-off, I can do away with making things beautiful and/or flexible. For one-off builds (again, whether it’s a webpage or financial model), most things can be hardcoded (e.g. unchanging interest rates, cell references and the like) and documentation doesn’t need to be too detailed (trust me on this though: documentation should still be done. People have a habit of waiting till the day after you forget what you did to ask you how you did it.)
If there are going to be many iterations, then I ask myself, what’s likely to change?
I once built a financial model containing over 30 options from which business users could pick and choose to determine what affected the final number. The model didn’t start of with all the options straight off the bat, and was in fact supposed to be a one-off. But after hardcoding and then manually changing what users needed multiple times within the same day (even though they “were quite certain” on what they wanted early on), I realised the flexibility of options, despite the longer initial development, was worth doing. I built the options on a very granular level so users could say, “I want option #1, #5, and #29” and have the affected numbers come up immediately.
Focusing on what’s more likely to change, and ignoring those that won’t, will allow you to save plenty of time. In that same model, I didn’t bother with ensuring formulas didn’t get broken when headings changed, because I knew they weren’t going to. (But I have certainly done this before; in some applications I’ve written, the source data had headings manually typed in, and almost every other week some variation of what was basically the same thing would get put in. I used regular expressions to ensure anything that looked like a header was treated as a header.)
Who and what is this report for?
Depending on the needs of the request, you could very well end up spending hours on something that should take only minutes. I have encountered many times someone coming to me for numbers in which I thought details were needed (or would be useful). I’d spend far too long extracting and formatting really granular data, when all the person needed was a “ballpark” figure.
And when you’re sending that consultant who is requesting for your company’s sales figures the information he needs, make sure you’re not giving him more than he needs. Does he really need to see the invoice numbers? Or customer IDs? Or costs?
Designing for maintenance
A few years back while taking the train I saw an engineering student’s lectures notes on “designing for maintenance”. I’m not from an engineering background, but because I happened to be mulling about on what software to use for a website I was developing, the concept of designing for maintenance struck me like Eric Clapton’s fingers on a guitar string.
Beautiful. Smooth. And oh-so-right.
The two main pieces of software that I had been considering were pretty distinct. One had a very developer-friendly, Linux feel. The other had a very polished, user-friendly Apple feel. The former catered to my nerd needs, while the latter catered my aesthetic aspirations (an aside: the very word ³aesthetic² is surprisingly pleasing to the eye and ear).
Though at first I was kept in a 50/50 bind between the two, after getting exposed to this idea of “designing for maintenance”, I realised that I really needed to go for the more polished and user-friendly one. Though I was helping to develop the website, I wasn’t going to be running it or doing the day-to-day maintenance of the site.
I think that maintenance of software (including spreadsheets) is something that’s missed by far too many people. If you know you’re not always going to be around to maintain the software, make sure it’s easy-to-understand and that everything’s well documented (even if it’s in an e-mail). Keep in mind that it isn’t all about you, but rather about the end-user, too.
Well, that’s about what I have for now. Would love to hear your thoughts on this. If you have any.