segunda-feira, 13 de janeiro de 2014

Entrevista Exclusiva - Fred P. Brooks - Criador do S/360

É com grande prazer que publico abaixo a entrevista exclusiva que fiz com Fred P. Brooks ,  em Agosto de 2011.  

Fred p. Brooks, junto com Gene Amdahl e G. A. Blaauw, formou o trio de arquitetos do S/360, sendo que os dois últimos abandonaram a IBM antes que o projeto chegasse a seu fim. A partir de então Fred P. Brooks conduziu todo o projeto, acumulando as funções de arquiteto e gerente geral do projeto.

Fred P. Brooks foi o primeiro a ter acesso a esse blog e fez a Abertura Oficial Virtual, no último dia 13 de Janeiro.


DR:  What was the IBM main motivation to launch the S/360 project ?      
FB:  Four things were big:

A. All of our product lines were running out of addressing capacity, and there wasn't room in the existing architectural frameworks to add more. So one or more new computer architectures had to be devised.

B. IBM's first integrated-circuit technology was coming down the pike with potential large cost reductions, performance enhancements, and reliability improvements. So it was the right time to provide a new product line that would capitalize on the new technology.

C. By 1961, we had recognized the potential of combining computing and communications, so making teleprocessing (remote terminal access) systems promised to provide whole new modes of use and usability, and hence a whole new market.

D. There was a vision of unifying the six diverse product lines, spread across two divisions, into one single coherent one. 

DR: I expected to see in this answer a reference to the application binary compatibility delivered by S/360 in contrast to the previous machines .
Reading books and documents, I tough this was a major design point of S/360 architecture [YES] and one of the selling points that contributed to the machine's success [YES].
FB: It was, and it was proposed in the SPREAD report, but it was not one of the motivators for convening the SPREAD Task Force to define a new product line.

DR:  What challenges did you face during the project ?
FB : 
A. Whereas computer engineering had some twenty years of history by 1964, software engineering was brand new, as was the notion of an operating system that controlled a computer instead of an operator doing it. The software challenges were by far the largest of the development challenges. See Pugh, Johnson, and Palmer's Chapter 6. 

B. After first deliveries, there were manufacturing challenges

C. My biggest management challenge was creating a unified product line across three semi-autonomous divisions, one of which consisted of companies and laboratories in many countries. The laboratories with substantial responsibilities for the System/360 product line were in six countries, under seven managements. Not as bad as Airbus, but similar. 
I have Pugh's book . 

DR: Could you imagine the success S/360 would make for IBM ?
FB: Yes, we imagined the nature of the success. I'd say we underestimated the sales magnitude by at least half. More surprisingly, we grossly underestimated the durability of the product line. I predicted 25 years. It's been 47, and the IBM mainframe line and its operating system softwares are still going strong, in direct evolutionary descent from the parent products. 

DR: What were the key success factors for the S/360 project ?
A. A wonderfully competent team of people in many specialties, including technology, product development, sales, customer service, and management.

B. A bold top management, willing to bet the entire company on one giant risky effort, in trying for a giant success. 

DR:  How do you define the impact S/360 system made in the marketplace ?
FB:It dominated the computer business at once. It maintained that dominance until the minicomputer revolution and the microcomputer revolution.
Even today, the S/360 family defines the "mainframe" segment of the market, which continues to be very useful and very profitable. 

DR: How do you assess the Mainframe evolution until these days ?
FB: I'm not close enough to all of today's computer developments to make such an assessment.

DR: How do you assess the contribution S/360 made for the IT industry ?
FB: See the "Assessment" sections in The Design of Design. Pages 323-327; 341-343, 

DR: In your perception, is there other technologies that made similar impact in business like the IBM mainframe ?
FB: Sure, lots of technologies have each revolutionized business: 
Standard coinage (Turkey?, 550 BC)
Paper money
Double-entry bookkeeping (Manucci, Florence, 13th century)
The computer itself
The telegraph, the telephone, and then the cell phone; radical changes in communication
The printing press, and then the typewriter, and then the copier
The punched card system
The railroad, and then automobile; enabled the incredible distribution system that drives our integrated economy
The airplane

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