Would be interesting to see a solution of the reverse process i.e. given an image or definition of a final model, create a bill of materials and (within various bounds) output step-by-step instructions to create it.
669 karma · joined September 10, 2013
The secret to estimating for scheduling is you only really need to answer this for the critical path. The hard part is defining and uncovering what the critical path actually is, and rarely is that ever achieved in projects or programs with the necessary accuracy or reflective of reality. This is why the critical-path is often seen as a myth, and perhaps it is, but like most myths it has an important message. There will be a subset of the project that requires a priority of focus to ensure success (in time, cost, or value delivered)
Assuming a narrow range of effort but a desire to be complete as soon as possible (because money costs money), luckily, most of the time you don't need to define the critical path exactly, to do so would be nigh impossible anyway, you only need to define it to a comfortable level of abstraction which is as free from external dependencies as possible, because, as humans we are flexible; sometimes the details change and we can accommodate that on an individual basis. The sticking point is the complexity of involving many people, or skills, or processes, or settings, or conditions. At some points this will work for you, and at others against you, something else will vy for criticality and you must then understand it.
The year is 2022. You're head DBA at the hot new social site, SupaRate... Your startup is seeing eye-boggling growth because everyone loves sharing their positive AND negative ratings restricted to UNSIGNED TINYINTs.
Why Unsigned? Because! How do you know if it's positive or negative? There's a VARCHAR(256) field for that, duh.
Make sure you have the right model for you.
When you are working to specific locations at each end it is a really tricky problem, but local grids like the ones described here help. I've worked on rail projects for mines in remote areas that need a few hundred kms of new track and span across "zones". The problem is exacerbated (at least then, early 00s) by the way you represent these in various CAD products, especially when sharing data between them. There are two main 3D modeling kernels that most popular professional CAD products rely on, both from the 70's 80's with minor updates neither 64bit native. Why is this an issue? Well, you see, the standard for civil design is to model in "real world" coordinates. That means you could be dealing with a file at the resolutions of mm for engineering purposes, but thousands of kms away from the origin. Now we enter the world off floating point calculation errors and subsequent kernel issues.
There are ways around it. Essentially offsets that move the origin of the file temporarily with a note to itself that everything must also account for the offset before displaying in the UI. But it can get confusing, fast, every product does it its own way and may not recognise this trickery. Working digitally with sparse real world reference data of varying qualities can be a big risk. I remember being in a large workshop with two surveying companies, our client and some civil engineers. I was horrified that I knew more about the various grids and their issues than any one else. I did one unit of surveying at uni, not long before and had to do a lot of research to get my head around the issues. These people were meant to be the experts.
The good thing about linear projects is that on those scales you can usually get somewhere where you can "work it out" on site (i.e. fudge it to make it fit). But It potentially affects everything, like, how many meters of track are we ordering? What contingency do we need? What are our expected mass haul volumes and estimated fuel costs? How big should we make our margin of error? It'll all work itself out, it'll just cost.
What happens when we start building beyond the planet and need to accomodate for curvatures in space time? Even ones that are brought about by the very thing you are building?
I try to as well, I had to rewrite that comment several times to be bit more generous but had to leave it where it was. It's hard - Ironically it comes from a place of wishing the world would be more generous to you. Beyond regular therapy I don't talk openly about this, both for this reason, and as I had been struggling with, and treated, for depression for over 20 years (which it now turns out is exacerbated or even caused by the untreated ADHD).
I've spent an incredible amount of effort and energy actively hiding this fact and any consequences from employers, teachers and loved ones out of fear of what it would mean for my already difficult to maintain status quo. I've seen what the stigma of mental health can do to ones career and future opportunities (unless of course you are an active and visual advocate, campaigner as well as your normal role).
As someone who also fights an internal battle with my diagnosis 24/7, comments like this are not helpful and can even be hurtful.
Would you ask someone with a hearing aid how they could be sure they were deaf? Or someone wheelchair bound how they could be sure they can't just walk if they try hard enough?
The world of work that we have made for ourselves as a society can be as inaccessible as the built environment can be to those who need accommodations to move around it safely.
Edit: After reviewing the snippets below looks like the script has gained sentience.
Haines, M. M., Stansfeld, S. A., Job, R. F. S., Berglund, B., &Head, J. (2001a). Chronic aircraft noise exposure, stress responses, mental health and cognitive performance in school children. Psychological Medicine 31, 265-277.
And features in a brief meta analysis which some may find interesting:
Matheson, M., et al. "The effects of chronic aircraft noise exposure on children's cognition and health : 3 field studies." Noise and Health, vol. 5, no. 19, Apr.-June 2003. Gale OneFile: Health and Medicine, link.gale.com/apps/doc/A164796669/HRCA?u=googlescholar&sid=bookmark-HRCA&xid=afd7e60c. Accessed 11 Apr. 2022. [https://go.gale.com/ps/i.do?p=HRCA&u=googlescholar&id=GALE|A...]
I skimmed the article but it seems to align with the literature back then. The thinking was during our evolution that high volume low frequency sounds would represent a precursor to mortal danger (avalanches, earthquakes, stampedes, thunder, wind) so we were attuned to secreting stress hormones in early response. Unfortunately, much of our urban built-environment is full of (human-made) constant low-frequency sources, although we appear to have adapted to a degree (HVAC systems in buildings, traffic, industrial process plants, airports and air traffic, explosions, concerts).
What isn't mentioned here, that I remember finding particularly concerning, was that while we seem to adapt, it's over our own time, as children we secrete more cortisol to low frequency noise than when we are adults... maybe some form of long term CBT I don't know.
I have no idea where my old paper is but I remember (and someone with more time might want to check/confirm this) one important study showed cortisol levels of children at schools close to Heathrow compared to out in the UK countryside and how this affected standardised testing. There were limitations, and of course you had to control for a range of factors, socio-economic, teaching staff etc, but there was some measurable negative effect (again no idea if this was repeated/corroborated).
The actual research I was doing was into our auditory perception of urban spaces. We took recordings of various urban settings and had participants listen and rate their emotional responses, if it felt "hot" or "cold" (and other adjective pairs), we also had them draw something to represent what they were listening too.
Our "findings" were pretty limited for a short undergrad project but it was interesting how we generally appreciate background chatter and live-music and generally fearful and cold from large flat surface reflected sound (empty city plazas).
There'll never be another Warney.
Other countries are watching these examples before undertaking their own versions.
The future could be built on it.
Who here hasn't been in a standup where a task was created against a CL that only had a title "FIX" (with the intention of filling it out later)
Complex Project Management in other sectors (construction) is starting to see life in this regard. Unfortunately much of the digital transformation of PM to date has focused on capture and reporting. Capture is capture but the problem with reporting is that nobody read the reports before and aren't going to read them now they are in dashboard with endless possibilities to slice and dice.
Automating insight is next but insight is difficult to draw when you have tens to hundreds of people building an often unreliable, usually bespoke, and piecemeal semantic model over time; quality and context is scattershot and the datasets not large enough on their own and not comparable to others.
[1] e.g. Clippy but AI that gets better as teams provide feedback: Does this issue relate to x or y? Is this issue A more important than this issue B? Was this issue A fixed by this PR B?
Personally... a significant portion of people like to "right". Some base their identity on it. People who are "right" in some things will often believe they are "right" in all things, which they may or may not be "right" in, even if they are sometimes unsure. It is these things that people will argue most vehemently in order to be "totally" right for any humility would be seen as total defeat. Some do it unconsciously, and some, more worryingly, do it consciously.
Best example was for fabrication of a large subsea structure. Often, these critical assets have material traceability requirements on-par with space exploration, producing thousands of pages of certificates and documentation along the way.
I.e. you need to prove and assure the provenance of every piece of material sitting on the 1km down on the ocean floor back to the assay report of the soup in the ladle at the forge when it was formed, and everything in between; material certificates, design specs, third party testing, mother plate to material stock to final cut part identification, and all the third-party witnessing and assurance along the way. Easy for small parts but cumbersome for 60tn structures with thousands of parts and welds.
When the requirement is 100% QA/QC coverage, linking IDs to certificates and other documents in each part of the chain meant we could easily visualise things and look for rogue elements like child parts pertaining to be from two seperate mother plates, or destructive testing coverage for all materials.
Not how it's usually done but it was a useful tool for communicating to other not so technical stakeholders and helping some on the project sleep easier. :-)
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Usually it's of little consequence and the stakes are low, but it's this general lack of skill in such a large population of people who are doing it poorly that gives estimation such a bad reputation in the first place. The idea of estimation is not incorrect, it's that people aren't taught how to do it properly in the first place and industry continues to propagate the myth that it's simpler than it is. Often because it's mandated by those who don't understand it themselves.
Having played in many types of industries I have a thesis that much of what we do in planning and estimating has had real benefit in some areas historically - where there are clear, repeatable, measurable observations, certain types of construction and fabrication - but not others due to their success being tied to the method alone without account for how the nature of what is being measured.
Monte Carlo has very real and valuable uses in critical path method scheduling, but, as with most things, only when used appropriately. Weather is something that fits well, because it is cyclic, we have a lot of data, we can, ahead of time, to some degree, have a likely view of where and when things like hurricanes/cyclones will occur in a given period.
In the Australian North-West Shelf where I used to plan O&G maintenance dive campaigns, knowing how long it takes to get to an area, a diver to get to depth, perform a task, return safely and leave the area is the easy part. "Everything going to plan"* we should be able to do these x number of inspections/interventions in y number of days. But weather is where you can come unstuck. Sea state matters, there is always some chance that you will have to interrupt or postpone on a day because of conditions. We know there are roughly x number of these days per cyclone season and roughly how long we might not be able to work for but pay full rates for crew, equipment etc.. An at risk period for weather goes on to the end of the schedule as contingency and is drawn down as needed, but in some scenarios where in the network of activities these multi-day events occur can have varying impacts. Inserting a three day stand-down early on could have a greater impact on the end date than a three day stand-down right near the end if at the earlier time you are doing things that must be done in a continuous sequence with - if interrupted - will need you to repeat again from the beginning. Luckily there are tools we can use to not just look at the net effects of activities in a schedule network having their own distribution curves, but also injecting events, again with their own probabilities, randomly throughout the network during the run.
This gives you a much greater insight than a 'P90' estimate on your critical path, it gives you the sensitivity of activities in your network.
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This all assumes, of course, that what you have modelled (planned) reflects reality to some degree. A bad schedule with bad bounds will give you a bad result regardless. It doesn't matter how many times you simulate it.
*it rarely does
[https://www.oecd.org/tax/beps/]
Groups where the ultimate parent is responsible for roughly over 1Bn in revenue are required to submit Country By Country Reports covering all cross border transactions their details and their transfer pricing methodology, and, in many cases, the underlying documentation of those transactions (contracts, loan agreements etc.). These are digitally submitted via your local jurisdictions Tax authority and shared with all member countries. Companies as part of that group are required to lodge more detailed information at a local level on just their cross border transactions with others in the group. This allows for some level of check that information being reported is globally consistent between tax authorities, who are then able to identify and place controls on unwanted behaviours.
Fast forward to the final two years of high school. I was much healthier, didn't miss school but did terribly. Maybe undiagnosed attention deficit, maybe depression, which led to a lack of motivation once my grades started to slip + general adolescence and socialising.
That being said, I had a relatively privileged upbringing and depending on your definition(s) of intelligence I would be generally considered above average. (I would hazard a guess that, a lot, if not most of HN leans that way) If either of those things didn't hold I probably wouldn't be where I am today.
Power infrastructure on this magnitude requires an extraordinary amount of capital investment to set up. Who takes on their debt? The operating expenses for asset management and maintenance of a mature network are eyewatering when compared to their underground counterparts as there is a lot more numerous and frequent replacement activity for parts. Pole infrastructure may have a life span of 10-15 years but some parts will be replaced out every 3-5. Before you know it you pay for every pole 4 times over it's life. Now multiply that by several hundred thousand poles in a large network and then you start to get the picture. I'm not trying to be an apologist but I'm surprised from what I hear of American infrastructure that it's not a far more regular occurrence.
https://www.ted.com/talks/elizabeth_gilbert_your_elusive_cre...
6:02 - "And that search has led me to ancient Greece and ancient Rome. So stay with me, because it does circle around and back. But, ancient Greece and ancient Rome -- people did not happen to believe that creativity came from human beings back then, OK? People believed that creativity was this divine attendant spirit that came to human beings from some distant and unknowable source, for distant and unknowable reasons. The Greeks famously called these divine attendant spirits of creativity "daemons." Socrates, famously, believed that he had a daemon who spoke wisdom to him from afar."
Whoa! Whoa! Whoa! No Helix geometry in this office, are you trying to get us all killed?!