Managing Complexity - The aim of Designing Code

I was reading Code Complete and the chapter was talking about Design and it was saying one of the most important parts of Design is managing complexity.

This makes perfect sense really, the whole process of designing is breaking the problem into smaller more manageable bits. He states that humans struggle to comprehend one massive complicated piece of software but can understand it easier if you split it down into small subsections.

If you think about the way you start designing you work with large abstract ideas and then slowly work down into smaller and smaller sections, until you end up with lots of small sections.

What I like about the idea of Managing complexity is that it means you start with something simple and then battle with it to keep it simple. It reminds me of seeing the code for a design pattern or a piece of code my some Java ninja, it always strikes me how simple it looks (and then you think, I could have done that).

I also like the word complexity because it's at the heart of making reusable code, reducing the complexity using encapsulation, and cohesion. I also think of complexity as being directly linked to the number of classes linked to a class. e.g. coupling. A simple class/package has loose coupling and is linked to the smallest amount of other classes as possible.

This is easier to understand, maintain and test.

What strikes me about linking Design with Managing Complexity is it is explaining simply what you are aiming to do when designing your code and just having that in my mind will help me focus on the objective of managing complexity.

This chapter is actually a free download on the Code Complete site, so if you would like to read more, firstly I would suggest you buy the book because I am finding it very useful and interesting but if you would like a taster to see if you would like the book here is the link

http://cc2e.com/docs/Chapter5-Design.pdf

I have talked about this book before and given links to two sample chapters, if you want a rough outline of the book a list of the contents, check out my previous blog entry

http://hoskinator.blogspot.com/2006/06/design-in-construction-code-complete-2.html

expect to see me talk about more of the topics mentioned in this book