[frantz@netcom.com: Re: Promptness]

[Jonathan Shapiro]

Return-Path: <frantz@netcom.com>
From: frantz@netcom.com (William S. Frantz)
Subject: Re: Promptness
To: shap@viper.cis.upenn.edu (Jonathan Shapiro)
Date: Mon, 5 Dec 1994 17:23:02 -0800 (PST)
In-Reply-To: <199412051853.KAA01873@mail3.netcom.com> from "Jonathan Shapiro" at Dec 5, 94 01:54:33 pm
X-Mailer: ELM [version 2.4 PL23]
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Content-Length: 713       

> If we are talking about mission-critical hard RT systems, then
> expectations seem inadequate.  The customer won't be comforted by
> expectations when the Boeing goes down.  In this case, the contract is
> either formally met or it isn't.

But, sometimes the Boeing does go down.  There is technically no way
to garentee that a system will work.  No matter how much redundancy
you have.  Add as many nines as you want to the .99999... probability 
and it still isn't 1.0.

-----------------------------------------------------------------
Bill Frantz                   Periwinkle  --  Computer Consulting
(408)356-8506                 16345 Englewood Ave.
frantz@netcom.com             Los Gatos, CA 95032, USA