• Subject: Re: AS/400 Gasping For Air ??
  • From: "Simon Coulter" <shc@xxxxxxxxxxxxxxxxx>
  • Date: Sun, 10 Jan 99 12:59:24 +0100

Hello Denis, Pete, Glenn, Don, James,  et al.

I find it amusing that I received less argument from this list when I was 
signing my missives as 
shc@VNET.IBM.COM.  Hmm?

If you read my original note properly you will see that 2000 LOC was a 
"guideline for project estimation".  
ESTIMATION not absolute.  I tried to pre-empt those of you who think you can 
write more than 2000 LOC in a 
year by explaining what went in to that figure.  IT IS NOT JUST THE CODE! Most 
of you do not develop software 
under the same requirements as IBM.  (Jeez, I wrote 2800 LOC in 5 days on the 
Query Manager project so I know 
good people can do more -- I might tell you that story one day :) ).

Of course it is an average!  What else can you use for estimation?

I do not know if IBM GS use the same estimation value but I would suggest they 
don't.  Most of their 
development work is not likely to have the same requirements as the internal 
development.  However, I would 
bet the guideline is lower than you think.  There are other issues at stake 
with GS too, keeping a huge 
number of bodies in work, credibility, etc, etc, etc (There I go again, playing 
the Siamese King.)

While LOC is useful for estimation it is not a good measure of productivity.  
It is far harder to write 
concise code than verbose code.  There is no good way to account for the 
thought that goes into a program.  
It is easier to count the output rather than the input.  

Denis' questions are valid which is more than I can say for most of the others. 
 So let's deal with them.

12 years is too low.  Much of the code in OS/400 came from the System/38.  
That's why OS/400 is known as XPF 
internally.  eXtended control Program Facility -- many of you will remember the 
OS for the S/38 was called 
CPF.  The new lads and lassies have just learned something -- does that make me 
a geezer or do I have to 
remember toggling in the bootstrap code in Octal before I qualify?  So lets 
average over 20 years.

I think a 50% rewrite is too high.  The major rewrites I am aware of occured in 
the LIC when the RISC system 
were introduced (VLIC and HLIC combined in SLIC) and when the query engine was 
rewritten to be a bit more 
intelligent.  I'd guess that at about 30%-35% but don't hold me to it.  V2R3 
saw The New Programming Model 
(ILE) code come in which was mostly implemented in internal code.

Many of the new products available on the AS/400 have been ported from other 
platforms or areas in IBM -- 
that reduces the effort required.  Rochester are also under increasing pressure 
to get new stuff out quickly 
which impacts the quality (I am sure Al can provide comments on the quality of 
some releases of OS/400).

Rochester do layoff staff on what seems to be a regular cycle but they hire 
graduates also.  They seem to be 
offering packages to their experienced people (who earn more and therefore 
reduce payroll) and hire cheap 
college graduates as coding grunts.  If they stay long enough to become 
experienced they will be offered a 
package in turn.

I don't know how many staff are at Rochester currently but 3000 would not 
surprise me.  Also remember that 
much of the work was farmed out to business partners and other IBM 
organisations.  That is what kept me 
employed by IBM for 8 years.

I have chosen not to answer the questions specifically but rather provide a 
background explanation.  Has this 
helped?

Regards,
Simon Coulter.

//--------------------------------------------------------------
// FlyByNight Software         AS/400 Technical Specialists
// Eclipse the competition - run your business on an IBM AS/400.
// Phone: +61 3 9419 0175      Mobile: +61 0411 091 400
// Fax:   +61 3 9419 0175      mailto: shc@flybynight.com.au
// 
// Windoze should not be open at Warp speed.
//--- forwarded letter -------------------------------------------------------
> X-Mailer: Microsoft Outlook Express 4.72.3155.0
> Date: Tue, 05 Jan 99 23:38:17 -0500
> From: "Dennis Lovelady" <dennis@lovelady.com>
> To: MIDRANGE-L@midrange.com
> Reply-To: MIDRANGE-L@midrange.com
> Subject: Re: AS/400 Gasping For Air ??

> 
> Hi, Simon:
> 
> >And you get what you pay for :).  I understand there are 65 million LOC in
> SLIC and OS/400.  Reliability
> >doesn't come cheap.  I've said this before: Any project has 3 attributes --
> CHEAP, FAST, GOOD -- you get to
> >choose two.
> 
> OK.  This is interesting.  The AS/400 has been around for 12 years, right?
> Technically, much (most?) of SLIC and OS/400 has been written or rewritten
> MUCH more recently than that, but let's use that number for the moment.  Now,
> with 65,000,000 LOC, and at a rate of 2000 LOC per man year for 12 years, we
> have..... 2708 workers (excluding management, marketing, etc.) involved in
> the development of the AS/400 SLIC and OS/400?  Over a 12-year period?  Is it
> safe to say that 50% of that has been (re)written since V3's inception?  What
> was that, maybe four years ago? (I don't remember.)  Running the same numbers
> (32,5000,000 LOC over 4 years), we have 4062 actual workers involved in that
> development over a 4-year period?  Can these numbers be correct?  Hasn't
> there been a layoff or two in that time frame?  This is intriguing to me.
> 
> Dennis
> --
> Dennis Lovelady                    Simpsonville, SC
> mail: dennis@lovelady.com
> URL:  http://lovelady.piedmont.net
> ICQ:  5734860
> --
> CONGRESS.SYS corrupted.  Reboot Washington DC <Y/N>?
> 
> 
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