Responding to Change

During my stay in the US during our vacations this year I was able to collect some notes and reflect on some stuff in the real world and compare it with software development occassionally. Today I decided to do a write up on the “Responding to Change” value of the Agile Manifesto.

While finishing the book The Pragmatic Programmer I got confronted with some concepts that I also noticed in the real world. Early on in the Design Patterns movement I learned to decouple my code as far as possible to allow change to happen. Craig Larman and Robert Martin early on got me into this thought process.

Being a European there were quite a bunch of things different in the US as here at home. Here is a list of things I noticed and I was wondering how hard it would be to change them in our software system. Luckily most of the things I wasn’t able to find at all, whereas most major variation points like currencies or tax systems were also thought on. How does your software respond to change it to the US system? What about selling your software to a European customer? For the testers and checkers among you, would you test that your software supports these? Do you test your software supports these? Does your software support them? Here’s the list, make the test, build up your mind and maybe let me participate in your findings.

Currencies There are a bunch of currencies I was confronted with. Euros of course, Deutsche Mark in the past (does anyone know what a “Groschen” is?), US Dollar, Pennies, Dimes, Quarters, Cents (does your software support the ¢ sign?), Disney Dollars (you can actually pay with it in Walt Disney World ressorts or take them as a gift for your mates at home), …

Tax Maps In the US every single state has a different tax model, even every county can have it’s own. In Germany there are different taxes applied usually, the lower one for food, the higher one for the rest. In Brasil there are 27 states each with their own tax model. Tax laws seem to be the most complex stuff.

Distances Meters, millimeters, centimeters, feet, inches, miles, kilometers, bavarian ells, english ells.

Area sizes Square feet vs. square meters.

Volume Litre, cubicmeters, Gallons to name just some.

Temperatur How many degress Celsius is one degree Fahrenheit? Is 90 degrees Fahrenheit hotter than 30 degree Celsius? What about Kelvin?

Fuel prices How much is 2.59 USD per Gallon in Euros per litre?

Consumption Is a fuel consumption of 28 Miles per gallon the same as 5 litres per 100 kilometers?

Voltages 110V vs. 220V vs. 400V, AC vc. DC.

What did I forget? What hard to change facts do you have to deal with?