I was reading No Silver Bullet from Frederick P. Brooks, Jr. I was wondering about the meaning of the sentence “These gains flow from the transformation of computer manufacture from an assembly industry to a process industry”.
I want to report my first attempts to decipher this, in order to clarify myself and hopefully help others.
First let me modernize the terminology. “Assembly industry” seems a synonym for Discrete manufacturing, the production of items by assembling more simple components (e.g. cars), while “process industry” seems a synonym for Process manufacturing, the production of items by some transformations on source components so that the output cannot be converted back (e.g. food);
So Brooks is saying that computer manufacturing is experiencing the increase of price-performance ratio because over time computers are no more built like a simple assembly of simple parts (electronic parts and wires) but as a direct transformation of source materials into the final product (think especially about silicon transformed into CPU/SoC).
I draw the conclusion that the process manufacturing of computers (roughly translating to miniaturization) permits to obtain better performance with relatively low work with regard to discrete manufacturing, but this is a claim for which I haven’t searched any argument.
as other conclusions from Brooks, this seems to hold true at current days — smartphone and tablets are rapidly becoming as powerful as computer because of the process manufacturing of computers.
the only drawback of process manufacturing of computers is that their repair is quite difficult and/or expensive — in fact, food cannot be repaired but must be thrown away
Finally, I want to point out a useful article from Poul-Henning Kamp that helps clarifying the first chapter of the Mythical Man Month.