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I'm not sure that the author has experience in the aerospace software industry. Software development there is a totally different ball game compared to web site

I'm not sure that the author has experience in the aerospace software industry. Software development there is a totally different ball game compared to web site / consumer app development. Automotive is also very different though not to the same standard as aerospace. There are rigorous standards that will make your eyes bleed https://en.wikipedia.org/wiki/DO-178C https://en.wikipedia.org/wiki/DO-178C and you won't have any fun with the latest frameworks and toys. It's designed to be boring and safe. The development process is excruciating. I remember from my short experience fun things like the person who writes the spec is not allowed to write the code and the person who writes the code is not allowed to write the test cases. Code coverage is not enough. You have to try to cover every combination of branching. https://en.wikipedia.org/wiki/Modified_condition/decision_coverage https://en.wikipedia.org/wiki/Modified_condition/decision_co... But in the end as the Boeing example shows. If you have people willing to subvert the regulations for their own personal profit then things will break.

morelisp 5y ago
MC/DC coverage is weaker than path coverage, which is what you describe. MC/DC coverage is also not as useful outside control systems, as other large systems usually have more side effects and path interdependencies. Conversely, path coverage measurements are computationally intensive at best and uncomputable at worst.
someweirdperson 5y ago
Automotive: It looks really great for management, to minimize the liability risk. Look what great processes we have installed to avoid all kinds of problems. Reality: The code is written by the lowest bidder. This might be people with some form of formal qualifications, but also often is people who have no idea how a car is supposed to work, who do not even have a license to drive one. Imagine someone implementing a web app without ever having used a web browser. The specifications are written by non-software engineers, and more often than not they contain a code-like description of the software, without any significant explanation. That's code written by people with no clue about software. The tests may provide any coverage you can dream of, but they are unfit to detect any kind of bug. Which is obvious because the authors of the code and test have no idea about what problem the code is supposed to solve. And the only goal is to prove coverage not to find bugs. In the end it only works because there is different people, who know how cars work, and test everything manually. At that point, coverage is of no concern at all, and bugs stay undetected, but the result might be just good enough. Also, it helps that (from a pure software point of view) most automotive software isn't exactly highly complicated.

morelisp 5y ago

MC/DC coverage is weaker than path coverage, which is what you describe. MC/DC coverage is also not as useful outside control systems, as other large systems usually have more side effects and path interdependencies. Conversely, path coverage measurements are computationally intensive at best and uncomputable at worst.

someweirdperson 5y ago

Automotive: It looks really great for management, to minimize the liability risk. Look what great processes we have installed to avoid all kinds of problems. Reality: The code is written by the lowest bidder. This might be people with some form of formal qualifications, but also often is people who have no idea how a car is supposed to work, who do not even have a license to drive one. Imagine someone implementing a web app without ever having used a web browser. The specifications are written by non-software engineers, and more often than not they contain a code-like description of the software, without any significant explanation. That's code written by people with no clue about software. The tests may provide any coverage you can dream of, but they are unfit to detect any kind of bug. Which is obvious because the authors of the code and test have no idea about what problem the code is supposed to solve. And the only goal is to prove coverage not to find bugs. In the end it only works because there is different people, who know how cars work, and test everything manually. At that point, coverage is of no concern at all, and bugs stay undetected, but the result might be just good enough. Also, it helps that (from a pure software point of view) most automotive software isn't exactly highly complicated.