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Bartosz Wucke
07/11/05 08:14
Read: 1052 times
Tarnow
Poland


 
#97041 - Perfect vs Good Enough.
Responding to: Erik Malund's previous message
So we know you can't prove a design to be correct. You can't prove a program to be correct. Testing proves nothing. Yet you must test to remove errors tests would find.
The question is: How much?
The answer is: Until it meets (and safely exceeds) the specification tollerances. Including tollerance for probability of exceeding the tollerances. (you can't guarantee EVERY device you make will be fine. You can only guarantee at most one in x will fail, and that you will replace it at no charge, plus eventually the chance it will fail in a harmful manner is one in y, and you will pay compensations in case it fails like that.)

You can't prove the specification is correct, for the simple reason that specification is arbitrary. The usual specification, which you oppose so strongly is "It just works for me" - and in this case testing that it indeed works for me is perfectly sufficient. It doesn't mean the design isn't flawed. It doesn't mean there's no errors. But nothing means that, so why bother? You make the devices to perform certain tasks, not to make them showcases of perfection. If they do the task, it's good. If they don't, it's not good. If they do the task partially, though, or not always, you must answer how often, or how much of the task do you agree to be done wrong.
If you aim at perfection, not only you will never reach it, you will waste a lot of time and resources too.

List of 105 messages in thread
TopicAuthorDate
disciplined clear process for debugging        Payam Soltany      07/04/05 21:41      
   Use a scope!      Andy Neil      07/05/05 00:06      
   Design for debug      Andy Neil      07/05/05 01:00      
      comments      Erik Malund      07/05/05 06:59      
         Comments on comments      Andy Neil      07/05/05 12:27      
            In the eyes of the beholder      Erik Malund      07/05/05 12:35      
               budget      Andy Neil      07/05/05 14:46      
                  budget      Bartosz Wucke      07/11/05 06:27      
                     that is when it will be needed      Erik Malund      07/11/05 06:44      
                        unless...      Bartosz Wucke      07/11/05 07:12      
                           you do not get the point      Erik Malund      07/11/05 07:18      
                              shoud I?      Jan Waclawek      07/11/05 07:30      
                              Yes.      Bartosz Wucke      07/11/05 08:14      
                                 inconsequent      Erik Malund      07/11/05 08:28      
                                    no, no, no...      Bartosz Wucke      07/11/05 10:49      
                                       then why      Erik Malund      07/11/05 10:56      
                                          ...which means...      Bartosz Wucke      07/11/05 11:13      
                                             which you must verify which is more work      Erik Malund      07/11/05 11:27      
                                                Coding style...      Bartosz Wucke      07/12/05 01:00      
                                                   that's impossible      Erik Malund      07/12/05 06:09      
               9 out of 10 cats prefer it      Donald Catto      07/06/05 02:46      
                  corrections      Erik Malund      07/06/05 06:26      
                     Experience, not correction.      Donald Catto      07/06/05 07:26      
                        I'm curious      Erik Malund      07/06/05 07:35      
                           no ICE      James Hinnant      07/06/05 20:04      
         I like Serial Debugging      Neil Kurzman      07/05/05 12:50      
         re:ice      Jacob Boyce      07/06/05 12:25      
            Don't put the bugs in!      Russell Bull      07/07/05 02:27      
               your brain is your best debugger      Jacob Boyce      07/07/05 07:15      
                  not always so      Erik Malund      07/07/05 07:29      
                     blindness      Jan Waclawek      07/07/05 08:01      
                        Tell it to the gatepost      Andy Neil      07/07/05 08:18      
                           are you calling      Erik Malund      07/07/05 08:40      
                           Simpler help.      Bartosz Wucke      07/11/05 06:52      
                              clerical errors      Erik Malund      07/11/05 07:10      
                                 Re:      Bartosz Wucke      07/11/05 07:33      
                                    when quoting, be complete      Erik Malund      07/11/05 07:37      
                        re:blindness      Jacob Boyce      07/07/05 08:51      
                           testing      Jan Waclawek      07/07/05 09:04      
                              debugging is NOT testing      Richard Erlacher      07/12/05 07:25      
                                 not according to NASA      Erik Malund      07/12/05 08:23      
                                    What?      Richard Erlacher      07/17/05 23:55      
                                       unnecessary code      Erik Malund      07/18/05 06:26      
                                       read all about it      Erik Malund      07/18/05 06:32      
                                          that's the difference ...      Richard Erlacher      07/18/05 22:47      
                                             I agree with NASA, you do not      Erik Malund      07/19/05 06:09      
                                 terminology      Jan Waclawek      07/12/05 09:36      
                                    definintions?      Richard Erlacher      07/17/05 23:45      
                           when designing devices that can harm lif      Erik Malund      07/07/05 09:50      
                              re:don't do harm      Jacob Boyce      07/07/05 12:13      
                                 another article of interest      Jacob Boyce      07/07/05 12:52      
                  WYWIWYS      Andy Neil      07/07/05 08:11      
                     An old programmer's law        Slobodan Mandaric      07/11/05 03:26      
                        An Old Programmer's response      Andy Neil      07/11/05 03:48      
                           perfect communication      Erik Malund      07/11/05 06:46      
   hmmmm      Jez Smith      07/05/05 02:04      
      Learning.      Bartosz Wucke      07/11/05 07:19      
      Sorry Mr. Professional      Payam Soltany      07/11/05 18:48      
         don't read if they are boring      Erik Malund      07/12/05 06:12      
            Allright      Payam Soltany      07/12/05 07:12      
               as I said      Erik Malund      07/12/05 07:14      
   Thanks Payam!      Mehdi      07/05/05 02:08      
      Don't let Erik see that!      Andy Neil      07/05/05 05:09      
         Bad engineering      Donald Catto      07/06/05 02:35      
            I don't think it is bad engineering!      Mehdi      07/06/05 03:07      
               Calm down - it's only a joke!      Andy Neil      07/06/05 03:41      
                  Yes and no      Donald Catto      07/06/05 05:22      
                     Testing      Steve M. Taylor      07/06/05 06:06      
                        succesful testing does not prove the abs      Erik Malund      07/06/05 06:39      
                           The proof is in the pudding      Donald Catto      07/06/05 07:12      
                              you can't      Erik Malund      07/06/05 07:42      
                              Proving      Andy Neil      07/06/05 11:43      
                           successful testing!      Mehdi      07/06/05 10:01      
                           Bad testing      Andy Neil      07/06/05 11:49      
                              bad, maybe, but possibly complete      Erik Malund      07/06/05 11:57      
                                 Perfect vs Good Enough.      Bartosz Wucke      07/11/05 08:14      
                                    the slippery slope      Erik Malund      07/11/05 08:37      
                                       90% agreement.      Bartosz Wucke      07/11/05 11:05      
                                          then why do you discuss releasing progra      Erik Malund      07/11/05 11:16      
                                             I don't "release".      Bartosz Wucke      07/11/05 11:48      
                                                Is repeating part of the question an ans      Erik Malund      07/11/05 12:09      
                                                   Yes.      Bartosz Wucke      07/12/05 00:34      
                                                      not authority but knowledge      Erik Malund      07/12/05 06:18      
                                                         Where...?      Bartosz Wucke      07/12/05 12:08      
                                                            do you really think that anyone consider      Erik Malund      07/12/05 12:26      
                                                               The $3.000.000 machine      Jan Waclawek      07/12/05 13:31      
            Yes, but...      Bartosz Wucke      07/11/05 07:42      
   I have one more ...        Slobodan Mandaric      07/05/05 06:07      
      CVS or SVN        Benjamin Damet      07/05/05 06:19      
         ....      Benjamin Damet      07/05/05 17:33      
   re:ISR      Jacob Boyce      07/06/05 12:42      
      defeating a purpose      Erik Malund      07/06/05 14:08      
         re:ISR      Jacob Boyce      07/06/05 15:11      
   Wikipedia:: debugging (etc.)      James Hinnant      07/06/05 20:37      
   Another one for your list      Andy Neil      07/07/05 00:38      
   PC-LINT      Mahmood Elnasser      07/07/05 13:58      
      anyone not using it?      Erik Malund      07/07/05 14:21      
         re:anyone not using it      Jacob Boyce      07/07/05 14:26      
            PC lint cost about $200      Erik Malund      07/07/05 14:34      
               PC Lint      Jacob Boyce      07/07/05 14:37      
            PC lint cost about $200      Erik Malund      07/07/05 14:36      
               Not Always      Neil Kurzman      07/07/05 18:09      
                  amen to that      Erik Malund      07/08/05 06:03      
   All nice and pretty...      Bartosz Wucke      07/11/05 05:19      
      Noise problems?      Payam Soltany      07/11/05 19:01      

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