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=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,3a4656a5edc0dab4 X-Google-Attributes: gid103376,public Path: controlnews3.google.com!news2.google.com!fu-berlin.de!uni-berlin.de!not-for-mail From: Peter Amey Newsgroups: comp.lang.ada Subject: Re: Ada used in General Aviation (GA) applications? Date: Tue, 18 May 2004 08:58:03 +0100 Message-ID: <2gtu0cF6siikU1@uni-berlin.de> References: <409F69CB.8020604@noplace.com> <20619edc.0405120909.6ba1a793@posting.google.com> <40A35FF6.9050703@noplace.com> <87u0yivdwr.fsf@insalien.org> <40A8AD3A.6040803@noplace.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Trace: news.uni-berlin.de YkPpAG/WOcVW0ok4/Bg1EAYg5n8lLlUJELJCWtwoG1kd2Xm0A= User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.4) Gecko/20030624 Netscape/7.1 (ax) X-Accept-Language: en-us, en In-Reply-To: Xref: controlnews3.google.com comp.lang.ada:660 Date: 2004-05-18T08:58:03+01:00 List-Id: Jeffrey Carter wrote: > Marin David Condic wrote: > >> Keep in mind that I have done a study that showed a 50% reduction in >> development time and a factor of 4 improvement in defects. You may in >> fact be thinking of that very study here. I've made the statement here >> before. > > > One was a study in the domain of jet-engine control, which I think was > presented by some guy named Condic. Is there a link to this study? That > would be a nice thing to have. The other is the Rational/Verdix study in > the domain of Ada compilers, which is available on AdaIC.org. There are > other studies also available on the AdaIC site, such as John > McCormick's. They don't present their results in a comparable way, but > the general message is the same for all of them. > On the subject of defect rates, I think data from the Lockheed C130K (Hercules II) project is relevant. Independent V&V was carried out by the UK MoD (the lead customer). The V&V covered a variety of systems produced by a variety of sub-contractors in a variety of languages. All the software inspected had already been cleared to DO178B level A or B. The results showed that: 1. Significant errors remained despite the prior FAA clearance. 2. Code written in C had, on average, 10 times as many errors as that written in Ada (and 100 times more than that written in SPARK). 3. No statistically significant difference in error rate between level A versus level B systems could be found. See: "Software Static Code Analysis Lessons Learned" by Andy German, QinetiQ Boscombe Down. DoD CrossTalk Journal, November 2003. http://www.stsc.hill.af.mil/crosstalk/2003/11/index.html and "Correctness by Construction: Better Can Also Be Cheaper" (PDF 312kb) Peter Amey, Praxis Critical Systems Limited. CrossTalk Magazine, March 2002. http://www.praxis-cs.co.uk/pdfs/c_by_c_better_cheaper.pdf Peter