Software Safety Basics PowerPoint

[Editor's Note: Originally published on THE SHORTED TURN's WordPress.com site on 2009/10/11] 

Copyright © 2009 Gary R. Van Sickle

I ran across a better-than-usual PowerPoint presentation on the basics of software safety, somewhat cryptically entitled “Software Safety Basics”.  It’s slides for a CompSci course, so get it while it’s hot (i.e. before the semester ends):

http://www.csl.mtu.edu/cs3090/www/lecture-notes/Software%20Safety%20Basics.pptx

It’s essentially the standard CSci safety course introductory slideshow, following the standard format:

1. Here’s a bunch of costly/deadly software failures that happened.
2. Here’s basically what happened in each instance.
3. Here’s some definitions of the terms and concepts we’ll be dealing with for the rest of the semester.

By its very nature, it is extremely high-level and lightweight.  What makes this one better than average are a few things:

1. The standard littany of case studies has been updated for the 21st century, complete with good use of graphics.  I.e., not another rehash of the Therac-25 - except as sad footnote to an exactly equivalent failure which occurred with a different radiation therapy machine some twenty years later (2000).  [Italics mine.  And that's twenty Internet years.  Has our profession truly made no progress in all that time? - Ed.]
2. A good graphical representation of the Fault-Error-Failure model (see pages 21-22).
3. A good (and again very high-level) state-transition-diagram-like depiction of  a “Model of system failure behavior” (pg. 26) which is applicable to all systems, even if they’re completely ignoring safety considerations.

So take a look if you want a good high-level overview of this topic.

Until next time Gentle Reader, I remain,

Gary R. Van Sickle
President and CEO/Editor/Head Writer
The Shorted Turn