From mboxrd@z Thu Jan  1 00:00:00 1970
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
Subject: Re: ioctls, etc. (was Re: [PATCH 1/4] sas: add flag for locally
	attached PHYs)
Date: Mon, 24 Oct 2005 16:41:35 +0100
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To: Luben Tuikov <luben_tuikov@adaptec.com>
Cc: Christoph Hellwig <hch@infradead.org>, Sergey Panov <sipan@sipan.org>, Stefan Richter <stefanr@s5r6.in-berlin.de>, linux-scsi@vger.kernel.org, Linux Kernel <linux-kernel@vger.kernel.org>, Jeff Garzik <jgarzik@pobox.com>, andrew.patterson@hp.com, Christoph Hellwig <hch@lst.de>, "Moore, Eric Dean" <Eric.Moore@lsil.com>, jejb@steeleye.com, Linus Torvalds <torvalds@osdl.org>

On Llu, 2005-10-24 at 09:51 -0400, Luben Tuikov wrote:
> controls and how.  Understanding how the factory workers use it and what
> they expect.  Understanding the code (which may not be as easy).  Then it
> is rewritten so that it can be easily supported and maintained.

Very very rarely, because it means down time and supporting two systems
at once. Take a look at the australian customs fiasco or the british
passport office disaster to see why (actually almost any large
government IT project where politics dictated 'write new stuff so I can
announce it in parliament').

The smart factory update would occur piece by piece. Starting with the
most pressing problems (ie fastest ROI) and working to a plan that ends
up with the system modular and clean.

You don't turn a steel plant off for a software upgrade.