On Fri, Mar 5, 2010 at 1:14 PM, Andrey Fedorov <[email protected]> wrote:
> First, let me apologize if I came off as rude before - I didn't mean to, > was just in an aggressive mood. > Sometimes the anonymity of internet does that to us. > > The picture Alejandro drew of System B used the CRT notation developed by >> Dr Goldratt [...] An arrow between two processes shows that the tail process >> must first complete before the head process can commence. A 'banana' >> operator between two arrows shows that all the tail processes so joined must >> complete before the head process can commence. > > > Cool! I'd never heard of CRT before. Thanks for explaining it. Just to make > sure I understand, it's a two-color directed graph (the "bananas" are one > color, the "normal" nodes are another), with the restriction that each > banana node must have exactly one outgoing edge into a normal node? > > The bananas are the arcs that connect two or more arrows they mean logical AND. > I have found it to be a powerful tool for modeling program execution. > > > It's certainly a neat way to look at large programs. I'm not quite sure how > accurate it could be at describing biological systems or the like. > > It has been used to describe factories, distribution chains, etc. really big systems (big in the sense of their number of nodes and interactions) > On Thu, Mar 4, 2010 at 8:20 PM, Alejandro Garcia <[email protected]> > wrote: >> >> On Thu, Mar 4, 2010 at 3:09 PM, Andrey Fedorov <[email protected]> >> wrote: >> >>> The picture you gave isn't a system, it's a directed graph. I guess >>> you're implying anything you imagine to be a "system" can be represented as >>> a graph - but what *is* a system? >> >> >> Well it isn't a system in the same sense that a map isn't the terrain. I >> think people call those things a representation. >> > > Precisely! So we *are* on the same page. It's a representation which > doesn't always preserve a system's "complexity" (without defining > "complexity"). > No we are not in the same page. I'm pretty sure that if a map shows a mountain and I go to the terrain that mountain is going to be there. Same if the blueprint shows a wall and I go to the building that wall is going to be there (99.99% of the time) So since there are several systems that I can't see or touch or even being to comprehend without an accurate representation. I'd better got to know them. For example I can't see the entire USA or the entire planet but with a good map I can make pretty good Idea of how that system "looks". > So all I'm getting from your earlier point is that the CRT representation > of a system can't be used to define "complexity". So it's a crappy > representation, after all. > > The point of the diagrams was to show that some people think of complexity as the number of nodes + arrows in a system.(ie how many words it takes to describe it) While other people see complexity as the number of degrees of freedom (possible states) of the system. System A has 16 possible sates System B has 2 So in essence system B is equivalent to just one circle! Isn't that "simple" (Inherent Simplicity as Goldratt would call it) > If we *do** *want to define "complexity", we could put a constraint on > these CRT graphs, like "nodes have no state"? This is starting to smell like > the classical argument against OOP. > > Cheers, > Andrey > > On Fri, Mar 5, 2010 at 3:28 AM, Antoine van Gelder <[email protected]>wrote: > >> On 05 Mar 2010, at 03:20 , Alejandro Garcia wrote: >> > On Thu, Mar 4, 2010 at 3:09 PM, Andrey Fedorov <[email protected]> >> wrote: >> > The picture you gave isn't a system, it's a directed graph. >> >> >> Andrey Fedorov! >> >> You have failed to observe the bananas in System B! >> >> Directed graphs do not have bananas you dumbass! >> >> Don't you know anything? >> >> ;-) >> >> >> > I guess you're implying anything you imagine to be a "system" can be >> represented as a graph - but what is a system? >> >> >> Processes in living creatures, social organizations or other phenomena >> that are operating synchronously in respect of one another are usually what >> we mean when we speak of systems. >> >> Which I wouldn't know today if it weren't for a philosophy major with his >> regulation-issue bong. >> >> Specifically: >> >> The picture Alejandro drew of System B used the CRT notation developed by >> Dr Goldratt. >> >> >> Where there are multiple tail processes feeding into a head process >> without a banana operator joining them, the head entity will commence upon >> _any_ tail entity reaching completion. >> >> >> >> >> > Well it isn't a system in the same sense that a map isn't the terrain. >> > A blue print isn't a building >> > a paint isn't the object being painted. >> > >> > I think peoplo call those things a representation. Maybe I'm mistaken. >> >> >> You're not mistaken Alejandro. >> >> I understood exactly what you meant. >> >> >> >> > Also, you can define the "complexity" of a graph in any way you like. >> Until you show that this definition is somehow representative of the real >> world, you're just masturbating. >> > >> > >> > Ok for example in the real world the realization that is possible to >> know how a system with several interactions will behave in a predictible way >> is the basis of Systems Thinking and the Theory of Constraints. Both with >> huge impact in systems from manufacturing to epidemic distribution. >> >> >> _IF_ you'd have to walk him through CRT's first to explain what you mean >> _AND_ he has already made up his mind that you don't know what you're >> talking about about _THEN_ he's unlikely to sit still for the two or three >> days it would take for him to realize his mistake. >> >> ;-) >> >> Are you actively busy with any research or applications of TOC & Systems >> Thinking to hardware design or programming Alejandro? >> >> Also of interest: >> >> Akyil - "How The Theory of Constraints Can Help Software Optimization" >> http://www.drdobbs.com/development-tools/218101302 >> >> Rippenhagen, Krishnaswamy - "Implementing the theory of constraints >> philosophy in highly reentrant systems" >> http://portal.acm.org/citation.cfm?id=293172.293397 >> (*cough* >> http://www.2shared.com/file/11859475/5abe015c/p993-rippenhagen.html) >> >> - antoine >> >> >> _______________________________________________ >> fonc mailing list >> [email protected] >> http://vpri.org/mailman/listinfo/fonc >> > > > _______________________________________________ > fonc mailing list > [email protected] > http://vpri.org/mailman/listinfo/fonc > >
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