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What is software maintainability, and why does it matter?

Video [2:15], with soundtrack

What is software maintainability, and why does it matter?

Computer software is like people's thinking…

Let's start off by thinking about what software is. Hardware is more tangible than software, so let's start there.

The difference between hardware and software is like the difference between your body and your mind.

It's usually easier to change your mind than it is to change your body. But some people are set in their ways: it's hard for them to change their minds. And some software is like that too: it's much harder to change than other software.

Why does software maintainability matter?

What happens when you can't change a piece of software that needs to be changed?

The law is changing, regulations change, and infrastructure changes. Customers and users want new products and services. If you can't change your software quickly enough, you can't keep up, and you're going to fall behind. And that's why software maintainability matters.

Maintainability in software is like flexibility in people…

Maintainability is a measure of how hard or easy it is to change a piece of software, just like flexibility is a measure of how hard or easy it is for someone to adapt to new circumstances. Some people are more flexible than others, and some pieces of software are more maintainable than others.

How do we measure software maintainability?

We look for obstacles which cause programmers to make mistakes.

The more obstacles there are, the less maintainable your software is and the more likely it is that you will fall behind.

So that's what software maintainability is, and why it matters.

The harder your software is to maintain, the more likely it is that you will fall behind.

Want to find out more?

Get a sample of a Quick Scan

Send us five source code files, and we'll tell you how maintainable they are! And we'll give you your money back when you order a Quick Scan.

$ 167 £ 127 € 147 HK$ 1288

If you send us a piece of software, we can tell you how maintainable it is. We'll print it out, pick up a red pen and inspect it, writing our findings on the printed copy of the source code. Then we count the number of obstacles that we found, compare the total to the number of lines of code that we inspected, and plot the result on the software decay spectrum.

It's not expensive…

We don't use software to do this work: we have a network of programmers who carry out inspections for us. We don't need any tools, other than the red pen, because when you're measuring how hard it will be for programmers to analyze, modify and test the code that they and their colleagues have written, you need someone who can read code!

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The OSQR Group serves clients in 25 countries across the Americas, Europe, Middle East and Asia and makes extensive use of the IfSQ Standards for Computer Program Source Code published by the Institute for Software Quality, Cambridge, UK. We have offices in Palo Alto (CA), Cambridge (UK), Amsterdam and Hong Kong.

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