Skip to Content
Code Simplicity
book

Code Simplicity

by Max Kanat-Alexander
March 2012
Beginner
84 pages
2h 12m
English
O'Reilly Media, Inc.
Content preview from Code Simplicity

Appendix A. The Laws of Software Design

This appendix summarizes all of the actual laws discussed in this book:

  1. The purpose of software is to help people.

  2. The Equation of Software Design:

    image with no caption

    where:

    D

    Stands for the desirability of the change.

    Vn

    Stands for value now.

    Vf

    Stands for future value.

    Ei

    Stands for the effort of implementation.

    Em

    Stands for the effort of maintenance.

    This is the primary law of software design. As time goes on, this equation reduces to:

    image with no caption

    Which demonstrates that it is more important to reduce the effort of maintenance than it is to reduce the effort of implementation.

  3. The Law of Change: The longer your program exists, the more probable it is that any piece of it will have to change.

  4. The Law of Defect Probability: The chance of introducing a defect into your program is proportional to the size of the changes you make to it.

  5. The Law of Simplicity: The ease of maintenance of any piece of software is proportional to the simplicity of its individual pieces.

  6. The Law of Testing: The degree to which you know how your software behaves is the degree to which you have accurately tested it.

That’s it. Many more facts and ideas were discussed in this book, but these six items are the laws of software design. Note that of all of these, the most important to bear in mind are the purpose of software, ...

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.

Read now

Unlock full access

More than 5,000 organizations count on O’Reilly

AirBnbBlueOriginElectronic ArtsHomeDepotNasdaqRakutenTata Consultancy Services

QuotationMarkO’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.
Julian F.
Head of Cybersecurity
QuotationMarkI wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.
Addison B.
Field Engineer
QuotationMarkI’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.
Amir M.
Data Platform Tech Lead
QuotationMarkI'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Mark W.
Embedded Software Engineer

You might also like

Five Lines of Code

Five Lines of Code

Christian Clausen

Publisher Resources

ISBN: 9781449314750Errata