re level in c ubn tz zoo toronto edu henry spencer writes in article apr mksol dseg ti com mccall mksol dseg ti com fred j mccall writes given that i ve heard the shuttle software rated as level level out of how many also keep in mind that it was not achieved through the use of sophisticated tools but rather through a brute force and ignorance attack on the problem during the challenger standdown they simply threw hundreds of people at it and did the whole process by hand i think this is a little inaccurate based on feynman s account of the software development process before the standdown fred is basically correct no sophisticated tools just a lot of effort and painstaking care but they got this one right before challenger feynman cited the software people as exemplary compared to the engine people he also noted that the software people were starting to feel management pressure to cut corners but hadn t had to give in to it much yet among other things the software people worked very hard to get things right for the major pre flight simulations and considered a failure during those simulations to be nearly as bad as an in flight failure as a result the number of major simulation failures could be counted on one hand and the number of in flight failures was zero as fred mentioned elsewhere this applies only to the flight software software that runs experiments is typically mostly put together by the experimenters and gets nowhere near the same level of tender loving care none of the experimenters could afford it all work is one man s work henry spencer u of toronto zoology kipling henry zoo toronto edu utzoo henry news software ureply x x from wingert vnet ibm com bret wingert c ubn tz zoo toronto edu in c ubn tz zoo toronto edu henry spencer writes in article apr mksol dseg ti com mccall mksol dseg ti com fred j mccall writes given that i ve heard the shuttle software rated as level level out of how many also keep in mind that it was not achieved through the use of sophisticated tools but rather through a brute force and ignorance attack on the problem during the challenger standdown they simply threw hundreds of people at it and did the whole process by hand i think this is a little inaccurate based on feynman s account of the software development process before the standdown fred is basically correct no sophisticated tools just a lot of effort and painstaking care but they got this one right before challenger feynman cited the software people as exemplary compared to the engine people he also noted that the software people were starting to feel management pressure to cut corners but hadn t had to give in to it much yet as fred mentioned elsewhere this applies only to the flight software software that runs experiments is typically mostly put together by the experimenters and gets nowhere near the same level of tender loving care a couple of points on this thread we have been using our processes since way before challenger challenger in and of it self did not uncover flaws what mr spencer says is by and large true we have a process that is not dependent on sophisticated tools case tools however tools cannot fix a bad process also tool support for hal s the shuttle language is somewhat limited the onboard flight software project was rated level by a nasa team this group generates kslocs of verified code per year for nasa feel free to call me if you or your organization is interested in more info on our software development process bret wingert fax bret wingert fax
