From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,a2fcc2648d0bc573 X-Google-Attributes: gid103376,public From: Ken & Virginia Garlington Subject: Re: Ada for Boeing 777 Date: 1996/02/25 Message-ID: <31308F21.5E1D@flash.net>#1/1 X-Deja-AN: 141036263 references: content-type: text/plain; charset=us-ascii organization: Redhawk Kennels mime-version: 1.0 newsgroups: comp.lang.ada x-mailer: Mozilla 2.0 (Macintosh; I; 68K) Date: 1996-02-25T00:00:00+00:00 List-Id: Vance Christiaanse wrote (with editing): > > In article , Frank > Petranka wrote: > > > As someone who has used both Ada and C, I was suprised and disappointed > > that code written in Ada produced no fewer problems than code written in > > C. > > Two observations: > > 1) Published accounts of software development efforts tend to be highly > political documents. That may be, but from indirect information I've received, this article is fairly accurate for the 777. > > 2) The quotes you provided didn't mention any actual statistics and the > wording suggests that the Ada problems may not have been related to > the language itself, but to the compiler and tools. This is definitely an issue for embedded systems, particularly in aerospace. Many of these systems don't get to use the most popular processors/OSs for a variety of reasons. As a result, the compilers are not widely used, and there are more latent bugs. Some other observations: 3) My personal experience is that our switching from JOVIAL to Ada did not, by itself, cause large drops in the number of problems in our software. Of course, the operational defect rate of the F-16 flight control software (JOVIAL), so far as I know, is zero. As a result, it's going to be hard to beat that! What is happening (at least, I think it's happening) is that we are able to at least maintain that rate as the complexity of our applications explodes. Ada is a small part of maintaining that rate. It wasn't clear to me, but if the article was claiming that the number of problems in the newer (presumably more complex) Ada 777 systems was comparable to the (presumably simpler) systems written in other langauges, then that's an encouraging result. 4) A lot of the defects in software have nothing to do with software coding or design, particularly with the sort of software development process used in aerospace. They tend to be introduced at the requirements level. So, it's not surprising that large differences between languages don't occur in that environment. In a SEI Level I environment, it probably makes a bigger difference. 5) I'm seeing a lot of companies going to code-generation tools and other techniques to support domain-specific architecture development. I think this trend is also going to make the language choice less important in the future. For example, reusing an often-used "C" routine in a similar environment can often (but not always) be more reliable that writing an Ada routine from scratch.