What is a Software Defect?

CARE: Crash Analysis Report Environment

DATA (Dump Analysis + Trace Analysis) Facebook group
Please join the community of memory (dump) and trace analysis engineers. This group promotes scientific methods and memory dump-based worldview.

Twitter @ DumpAnalysis
You can now follow portal and blog news at DumpAnalysis on Twitter

LinkedIn Group Dr. Watson Enthusiasts
All about Dr. Watson errors and more. Get news, excerpts and progress reports about the forthcoming book The Science of Dr. Watson: An Illustrated History of Debugging (ISBN 978-1906717070)

2010 (0x7DA) - The Year of Dump Analysis
2011 (0x7DB) - 2020 (0x7E4) The Debugging Decade

Software can be considered as models of real or imagined systems which may be models themselves. Any modeling act involves a mapping between a system and a model that preserves causal, ordering and inclusion relationships and a mapping from the model to the system that translates emerging relationships and causal structures back to that system. The latter I call modeling expectations and any observed deviations in structure and behavior between the model and the system I call software defects which can be functional failures, error messages, crashes or hangs (red line on diagrams below):

Consider ATM software as a venerable example. It models imagined world of ATM transactions which we call ATM software requirements. The latter specifies ACID (atomic, consistent, isolated and durable) transaction rules. If they are broken by the written software we have the defect:

What are software requirements? They are models of real or imagined systems or can be models of past causal and relationship experiences. If requirements are wrong they do not translate back and we still consider software as having a defect:

Translating this to ATM example we have:

Another example where the perceived absence of failures can be considered as a defect is the program designed to model memory leaks that might not be leaking due to a defect in its source code.

Now we can answer the question ”What is a memory corruption?” which is the topic of the next post.

- Dmitry Vostokov @ DumpAnalysis.org -

           

Announcements

Coming Soon:

Debugging Notebook: Essential Concepts, WinDbg Commands and Tools

Crash Dump Analysis for System Administrators and Support Engineers

New Magazines:

Debugged! MZ/PE: MagaZine for/from Practicing Engineers


New Books:

Memory Dump Analysis Anthology, Volume 3

First Fault Software Problem Solving: A Guide for Engineers, Managers and Users

x64 Windows Debugging: Practical Foundations

Also available:

Windows Debugging: Practical Foundations

DLL List Landscape: The Art from Computer Memory Space

Dumps, Bugs and Debugging Forensics: The Adventures of Dr. Debugalov

WinDbg: A Reference Poster and Learning Cards

Memory Dump Analysis Anthology, Volume 2

Memory Dump Analysis Anthology, Volume 1

New Children's Book:

Baby Turing

2 Responses to “What is a Software Defect?”

  1. Crash Dump Analysis » Blog Archive » On Subjectivity of Software Defects Says:

    […] - The Year of Dump Analysis 2011 (0×7DB) - 2020 (0×7E4) The Debugging Decade If we adopt the model-based definition of software defects we can easily see that any changes to the model can surface the new unanticipated defects and […]

  2. Software Generalist » Blog Archive » Software Generalist Worldview Says:

    […] was recently revisiting my old post about model-based definition of software defects in relation to their forthcoming classification. When thinking I recalled a three worlds diagram […]

Leave a Reply