Under development

Posted on 27 Jun 2006 at 10:42

 

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This is a classic Extreme Programming (XP) project, in which you start off with the simplest design that will do part of the job and then keep modifying it in the light of experience. I know this sounds as if you're making it up as you go along, but it's more organised than that. You'll find links to sites with descriptions of Agile Programming and XP techniques plus a review of eXtreme .NET by Neil Roodyn at www.drsaxon.co.uk.

One of the main drawbacks of the XP approach is that it's impossible to determine what the cost will be at the start of the project. The person paying the bill has three options:

1. Define a budget. This means that the project finishes when the money runs out, whether or not it has all the desirable features.

2. Leave the budget open until the protagonists declare the job finished. Few people are willing to do this, for obvious reasons.

3. Abandon the XP approach and define exactly what they want up front. This includes paying for the requirements definition. Of course, the lack of willingness to do this is what makes it an XP project in the first place.

Bob had said "Just get on with it," so I've kept a detailed log of everything the program contains so that I can justify the bill. It has 459 features, 14 reports and nearly 5,000 lines of code, and that's without the specialist libraries, which could take the total past 20,000 lines. The bill is likely to work out at close to a pound a line, but that's way cheaper than the off-the-shelf package would have been for even one factory.

FEEL THE WIDTH

Well into the live development phase, we discovered a snag. The stock that had been arriving from suppliers using our labelling program was fine. The opening stock Katja had labelled herself, and she'd confused the width and height so the measurements were transposed. One of the stock searches looks for materials of a specific width, so with this data it doesn't give the right answer. The production staff are annoyed and Katja is embarrassed. It's a simple mistake, but how good, I ask myself, is my Finnish? Let he who is without sin...

Thank goodness the whole system is based on a SQL database. A simple script finds the offending items and swaps the width and height parameters. Katja is very grateful and leaves a voicemail message on my phone saying, "Thank you, thank you, thank you!"

Mrs R is in the office when I play it. On the speakerphone. Oops.

Author: David Robinson