I have in my possession the check list that was accomplished on the worst of our failures. This check list was signed, dated, and approved by the responsible authority. The <<missing item>> on the check list was argued over on site and never done. Check lists are not sufficient. They are a necessity but not enough. Systems need to be the simplest possible engineering design that will complete the task. The multiplicative probability of successes will then not result in a high probability of failure. This is (of course) not a perfect "law" since these are not independent probabilities but this definitely the system engineers "guide book to success". This is the first and last I will ever say on this particular matter. We have made mistakes but almost ALL of our mistakes are directly attributable to human failings and managerial fault lines. To me, this is mostly a dispassionate process. I do not treat foolishness lightly because that leads to a repeat of it but this is a tactic, not the goal.
Bob
Edward Cole wrote:
Exactly!
And at the risk of repeating myself: The people checking off the list should have someone checking their work. In other words do not trust one individual to be failure-proof. In previous work environs I had at least two other individuals checking over my work to capture errors and oversights!
With a good checkoff procedure/list, thorough project plan, and enough folks to double or triple check (esp. critical steps) there should be a high confidence in things going right. ***in a perfect world***
73 Ed - KL7UW
At 08:15 AM 12/15/2007, Joe wrote:
I'll agree with this completely. While we are NO AMSAT, we here at Near Space Sciences, (one of the balloon groups) have in the heat of the launch excitement have just plain forgot to turn something "ON"
Without a formal checklist, where everything must be checked off the list before liftoff, or lift off doesn't happen, something is bound to be missed. it happens on our simple payloads, i can not even imagine the complexity of a real AMSAT type of bird!
Joe WB9SBD
Robert McGwier wrote:
Yet again, a statement based on no knowledge of the real situation. MOST space failures are caused by exactly this kind of thing. A wrench left behind and falling and puncturing a tank. Incomplete testing of this or that and a SUPPOSITION that it was "Okay". Satellites not bolted down when everyone assumed it was and a $100,000,000 satellite falls to the floor. These space things are extremely complex and if every system had to be tested to perfection, none could afford them. The goal of a good trained space/spacecraft engineer is to design robust systems that have the really supercritical things testable and the rest, well, the rules for that are in the adjoining testing manual (the local religious book, for prayer).
Bob
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73, Ed - KL7UW ====================================== BP40IQ 50-MHz - 10-GHz www.kl7uw.com 144-EME: FT-847, mgf-1801, 4x-xpol-20, 185w DUBUS Magazine USA Rep [email protected] ======================================