Monday 15 March 2021

Post No. 1,798 - Cross Posting: P&IDs and other miscellaneous thoughts on thinking

This originally appeared on my political blog at https://politicalmusingsofkayleen.blogspot.com/2021/03/p-and-other-miscellaneous-thoughts-on.html.

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In the engineering water field (and other areas of engineering) we use what is termed a "Process and Instrumentation Diagram", or P&ID (or even just PID). It shows a diagrammatic view from "the side" showing tanks, connecting pipes, equipment and instruments - not in a physically representative way, an illustrative way: so two tanks connected by a pipe would be drawn as two rectangles with a line between them, but notes would provide the information a process designer would need.

As an example, that required information might be: 

  • the flow in; 
  • the kg/d of, say, organic matter (often indirectly measured as the amount of oxygen it will consume over - typically - 5 days, but a more comprehensive chemical test has been more widely used in recent decades [especially for computer simulation/modelling] );
  • the volume of the tanks, and maybe the minimum and maximum depths it that varies, or otherwise just the depth.

When I was taught how to start working with PIDs in the 80s, as a process engineer I wanted all the information I needed before me, in one place - so I did something radical: I put the flows and loads on the PIDs. 

Other engineers were bewildered - and still are. Their attitude seems to be: 

should not this great and worthy piece of information be given the honour of being worshipped on its own altar of information that we call a drawing?
and put that information on a PFD or somewhere else.

No, actually, it shouldn't. 

When you do that, for me to do a simple calculation such as, say, the average hydraulic retention time (HRT) in a tank, I look at the PID to get the size of the tank, then go hunting somewhere else for the flow and either memorise that or write it on a bit of paper, go back to PID, grab a calculator (no PCs in those days), and calculate the average HRT. 

My way, all I have to grab is the calculator. 

The traditional way was stupid and inefficient, and I consider the industries insistence on that to be obdurate in the extreme - although I will concede that for larger projects, where bits of work get divvied up to various subbies, that information is still needed. OK, so record it elsewhere, but let me also put it on the PIDs where I need it so I can do my job more time-efficiently.

I don't need all of the available information - for instance, minimum flows are needed to ensure that solids do not settle out in gravity pipes, but that does not impact on designing (specifying the performance requirement in terms of oxygen provided) for an aeration system.

Control systems are another one: yes, have a full blown control narrative, philosophy and drawings elsewhere, but let me put the links on the PID by showing a line from the dissolved oxygen meter in the aeration tank to the motor driving the aeration system. 

A lot of the problem is engineers making the mistake of thinking that what is best for large treatment plant is also best for the smaller plants that I've spent most of my life working on, and that is most definitely NOT the case. 

Another part of the problem is the information-worship that I alluded to above - in this sort of context, information is a graven image or idol to be worshipped: it must have a purpose, or otherwise it is a distraction. 

And managing that must be focused on ensuring it can be used efficiently, not worshipped - I mean, "stored" - more reverentially. 

Another example is correspondence, which used to be filed separately, collated as inwards correspondence, and outwards correspondence.

So, let's say you were reviewing a problem. 

  • first, you find the file where the problem was raised; 
  • then you go the other file, search through it until you find the reply; 
  • then you go back to the other file, search until you find the reply to the reply; 
  • and so on, ad infinitum - or, perhaps, ad nauseam.

In my opinion, it is best to group all matters relating to an issue together. 

Being able to do searches more efficiently with PCs IS NOT THE BLOODY ISSUE - IT IS STILL WASTING TIME. IT IS UNNECESSARY, AND A DISTRACTION AND THUS A RISK TO RESOLVING THE PROBLEM

We can, in this day and age, collate shortcuts to the key bits of information in a single folder, so we can go to one place, access the information, and use our minds more efficiently by focusing on the issue, not finding where bloody bits of information have been bloody hidden.

Information worshippers - er, I mean information "managers", or the IT department - often make this worse by developing new systems that worship the information more effusively, but actually cost time in finding the information when looking from the middle of a project/problem, spending time updating the shortcuts/links, and losing mental focus.

Maybe it is meditating since I was a teenager, but most engineers and IT people seem to be utterly clueless about the need to minimise expenditure of mental energy/effort on irrelevancies/ trivialities so you can focus on the task at hand. 

I think part of the problem these days is that so many people assume all the calculating and most of the thinking is done by computer software, and thus "it doesn't matter" if time is spent chasing bits of information, because you can toddle off and have a smoko while the computer does your work for you once the information is obtained. 

Bull. 

Anyone who thinks that should be sacked - or at least demoted.

Software gets developed for engineering applications that are common enough and significant enough and glamorous enough for people to make money and prestige from. 

The issue of glamour is an important one. One of the most common forms of wastewater treatment across the world is lagoons (note: I did not provide the Wikipedia entry as it is so seriously misleading - as is the bias in the general Wikipedia article on wastewater treatment) - low cost, although they require large area, and only provide secondary not tertiary (nutrient reducing) treatment, but the low cost often means it is all that can be done by poorer nations. Up themselves engineers tend to say "oh it's a lagoon so it's simple", but that's not true: it's less complex than an activated sludge process, yes, but there are still quite a few processes in the lagoons, and some of those (such as the interactions between sludge on the floor of the lagoon and what is happening in the water column, especially the generation of inorganic carbon that oxygen-generating but potentially eutrophic algae need). The fools who think lagoons are simple come up with simple and often ineffective equations (and often use wildly over-optimistic reaction rates - especially the US EPA manuals) - and the drive to build them means they are often undersized, therefore don't work, therefore engineers tend to wrongly think that more expensive - and glamorous - approaches such as activated sludge should be built.

A lot of this would be resolved if only people would know themselves, but, in my experience, too many engineers lack self awareness/reflection - they are NOT autistic, which used to be a widely used and inappropriate joke about engineers, they're flawed as human beings, as we all are, albeit in different ways. 

Some of my recent reading has more on the topic of the flawed thinking and biases of engineers. the following is from from "Gandhi: His Life and Message for the World (Signet Classics)" by Louis Fischer (Amazon):

"Industries are of course necessary, but in many Asian and African countries they bring prolonged mass unemployment and misery rather than mass prosperity and useful leisure. Persons displaced by a complex lathe are not soon absorbed into other jobs; they starve." (a lot of engineers of my generation are so bewitched by the glamour of technology and complexity that they are utterly bewildered by this human consequence of their addiction)

"Challenged to boredom as to whether he objected to machinery, Gandhi exclaimed, “How can I when I know that even this body is a most delicate piece of machinery? The spinning wheel is a machine; a little toothpick is a machine. What I object to is the craze for machinery, not machinery as such. Today,” he continued, “machinery merely helps a few to ride on the backs of the millions. . . . I would make intelligent exceptions. Take the case of the Singer sewing machine. It is one of the few useful things ever invented, and there is a romance about the device itself.” He had learned to sew on it. And would you not need big factories to produce such devices? “Yes,” he agreed."

"The individual’s strength of spirit must at least keep pace with the expansion of bureaucratic, economic, and scientific power; otherwise he will be beaten into a robot slave. On the outcome of the race between man and power depends the future of modern civilization. . .  “Gandhi has straightened our back and stiffened our spines,” Nehru said. Power cannot ride on an upright back." 
That last point is where the lessons I've been writing about here, about focus, avoiding glamour, understanding and enabling good, clear and accurate thinking, start to flow in to the political sphere this blog is focused on. From "The Power of the Powerless (Vintage Classics)" by Václav Havel and Timothy Snyder (Amazon):
"That is, if ideology originally facilitated (by acting outwardly) the constitution of power by serving as a psychological excuse, then from the moment that excuse is accepted, it constitutes power inwardly, becoming an active component of that power."

I don't have time to elaborate on those quotes as I should, but here's another quick thought for you: 

  • neoliberals conflate public demand and need, and restrict "cleverness" to "that which increases profit". 

Don't be mentally lazy or blind, be psychologically astute (know thyself, know thy world, and make informed choices), and be competent at being human