North American Network Operators Group
Date Prev | Date Next |
Date Index |
Thread Index |
Author Index |
Historical
Re: Limits of reliability or is 99.999999999% realistic
- From: Shawn McMahon
- Date: Mon Nov 27 11:31:44 2000
On Mon, Nov 27, 2000 at 11:07:34AM -0500, Marshall Eubanks wrote:
>
> In spacecraft work, JPL has found that, if you did not
> strive for "5 sigma's" or even "6 sigma's" of reliability, then
> there would always be something you hadn't counted on that would
> drive reliability to zero.
NASA's needs don't reflect our needs.
If my router fails, I can get to it to fix it in seconds, and if I need
to replace it I don't have to wait five years to launch and another year
to reach the target.
If I have to have a replacement overnighted, I'm still only down a day,
not a decade.
Also, NASA's budget for a POP on Mars is a little higher than my budget
for a POP in Colorado Springs. Hell, their budget for a single lander
is probably higher than my budget for an entire data center.
Attachment:
pgp00031.pgp
Description: PGP signature
|