The so-called experts will tell you it can’t be done; it is not possible to create bug-free software, at least at low-cost for a non-trivial application. Now it seems, we have our first documented case of ostensibly zero-defect software.
Continue reading “Correctness by Construction: Praxis Scores!” »
Until Agile, software processes in general focused on larger projects. When applied to smaller projects they can become cumbersome and inefficient. Agile has demonstrated its value on relatively small projects, but it does not scale up well, and in my opinion some of its core tenets are incompatible with safety-critical development.
I just finished reading Steve McConnell’s Professional Software Development: Shorter Schedules, Higher Quality Products, More Successful Projects, Enhanced Careers. This is not a book about languages, software design, or coding techniques. It is a book about being a software professional, and about managing and leading software professionals. It is a book about the state of software development as a profession, and about what we should aspire for it to become. All that, and it is an interesting read.
Continue reading “Professional Software Development – A Book Review” »
As I’ve said before, MC/DC analysis is the bane of Level-A development under DO-178B. It is not well understood, either by developers or by verification engineers. Automated analysis tools will perform the analysis, but that may not occur until verification has begun. Fixes at this stage are far less desirable than avoiding issues in the first place. So how do we ensure that MC/DC issues do not occur in the first place?
Like many veteran software developers, I am sold on the value of defensive programming. It seems that no matter how thorough the requirements, nor how good the design, things can go wrong; and I’d like my code to be able to handle it. So imagine my surprise when no less than a DER provided me with a perfectly valid and well-reasoned argument to discard defensive programming techniques altogether.
After my oh-so-recent review of Best Kept Secrets of Peer Code Review, I followed up with the author to inform him of the review. I also took the opportunity to tell him that I disagree with him on a few points, not the least of which is the concept that finding a larger number of defects is good. His reply was gracious, and I hope to have an opportunity to further discuss some of these points with him. Meanwhile, I was inspired to carry on my rant here on the home front.
I just finished reading the “Best Kept Secrets of Peer Code Review (Modern Approach. Practical Advice.)“, by Jason Cohen. While this book is available from resellers at Amazon.com, for the time being it is being offered free of charge from Smart Bear Software, a software tool company founded by the book’s author. Continue reading “Best Kept Secrets of Peer Code Review – A Book Review” »
