On Wednesday, October 14, 2015 at 4:25:37 PM UTC-4, dklei...@gmail.com wrote:
> On Tuesday, October 13, 2015 at 9:39:00 PM UTC-7, Charles Bishop wrote:
> > In article <29bc764b-14b4-4f47...@googlegroups.com>,
> > David Kleinecke <dklei...@gmail.com> wrote:
> >
> > > On Monday, October 12, 2015 at 9:24:16 PM UTC-7, Charles Bishop wrote:
> > > > In article <606f03b1-1662-4661...@googlegroups.com>,
> > > > David Kleinecke <dklei...@gmail.com> wrote:
> > > >
> > > > > On Monday, October 12, 2015 at 1:20:36 PM UTC-7, Charles Bishop wrote:
> > > > > > In article <d7r8cu...@mid.individual.net>,
> > > > > > Robert Bannister <rob...@clubtelco.com> wrote:
> > > > > >
> > > > > > > On 9/10/2015 12:02 PM, Charles Bishop wrote:
> > > > > > >
> > > > > > > > In new work, the electrical work is done before the painters show
> > > > > > > > up
> > > > > > > > (they're usually last, or nearly so of the trades) The wires are in
> > > > > > > > the
> > > > > > > > boxes, but there are no outlets, switches or coverplates in place.
> > > > > > > > You
> > > > > > > > can see the wiring inside the box.
> > > > > > >
> > > > > > > In the building trade everything seems to be designed so that the
> > > > > > > tradespeople arrive at the wrong time. The bricklayers come, but the
> > > > > > > footings haven't been dug yet so they go and start another job - a
> > > > > > > month's delay. The plasterers arrive, but the plumbing and electrics
> > > > > > > aren't finished yet, so they go away - six weeks delay. And so on.
> > > > > > > I've
> > > > > > > seen houses go up and be finished within a couple of weeks, but
> > > > > > > mostly
> > > > > > > the tradies are working on half a dozen different jobs and turn up
> > > > > > > when
> > > > > > > they feel like it, which rarely fits the plan.
> > > > > >
> > > > > > This seems to be the belief, but it wasn't so on jobs I was on, mostly.
> > > > > > There are slippages, and change orders, but mostly these were small
> > > > > > jogs
> > > > > > in the schedule.
> > > > >
> > > > > Ever been faced with a bubble chart?
> > > >
> > > > No, I haven't. And a quick Google didn't leave me with even a vague idea
> > > > of how it would be used in construction projects.
> > >
> > > It would seem like a natural - but maybe construction projects are too
> > > simple to need them.
> >
> > Any chance I can get a description of what they do (what is represented
> > by the circles and colors) and what they're used for?
> >
> > I can possibly see a use to determine the size and timing of a
> > particular part of a job, even showing where some overlap. However the
> > other chart mentioned is better for this.
>
> I haven't read this thresd to end (13 hours to go) but I'll answer
> anyway.
>
> A bubble chart is a big (blackboard-sixe) piece of paper (doubtless
> vitualized these days) with ovals all over it. In each oval is the
> name of a task. There are arrows from oval to oval showing which
> tasks must be completed before the next starts. Each task has a time
> to complete. By a fairly obvious algorithm you can calculate how
> long it will take to finish everthing. There are one or more critical
> paths - paths that take that maximum time.
>
> A manager will put his attention to the tasks on the critical path
> because if one them takes longer than expected the whole project is
> going to be delayed.
>
> Bubble charts are best known in the context of PERT - which stands for
> something - which adds sophistication by giving each task a statistical
> distribution of completion times. Then you run the timing algorithm
> Monte Carlo style for a couple of hundred times and get a statistical
> distribution for how long the entire project will take.
>
> You can be even more sophisticated and insure that resources assigned
> to each task are available when the task is to be done.
>
> Complex - but workable. I don't know that anybody is using it today.
>
> PS: I believe I remember an A. E. van Vogt story where they were
> building a new class of spaceships and once the assembly line started
> they were planning to output one every minuute for fifty years. That
> would require serious advanced planning.

P.E.R.T. stands for Program Evaluation and Review Technique (on a PERT chart or a Perchart board - or a chart board or a drawing board).
===============_
(operations) A diagram which uses the symbols and notations of program evaluation and review technique to depict the flow of dependent tasks and other events in a project.

Your Dictionary
-- https://www.yourdictionary.com/pert-chart
================

I was just looking at an early '70s crime series episode starring Michael Douglas and Karl Malden (episode: "The Glass Dart Board", ep#74: s#4e#2 "The Streets of San Francisco"). They discussed using a 'P.E.R.T. chart'.