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efficiency is a two-edged sword


  • I originally thought the business world was going to be all about efficiency. As I moved slowly through the economy things began to change. Efficiency dominated dishwashing and warehouse work, but in programming it was more balanced with other goals.
  • Then I started reading elite technologists and thinkers. Here the gradual change became a full flip. Their relationship to efficiency wasn't one of balance. It was a love/hate thing with a nice heaping scoop of the latter.
  • This was pleasantly surprising. I don't mind grinding, but I want there to be slack in the world too. I'm glad the best thinkers see a place for the hammock as well as the keyboard and tool belt. At least 👤 Rich Hickey and 👤 Eliyahu M. Goldratt do, though not 👤 Hyman Rickover as we'll see.
  • Problems with efficiency-based thinking
    • It doesn't take into account human nature
    • It leads you to optimize the wrong thing
        • The Goal is one of the most famous business novels ever and it's a 300 page rant against local efficiency.
        • The thesis is that in a flow system like a factory you shouldn't try to maximize the time in use of the people and machines at every station.
        • Rather you should figure out where your system is bottlenecked, make that step efficient, and happily leave slack everywhere else. That way the other stations always have excess capacity to prevent starvation at the bottleneck.
        • Here's an excerpt to illustrate. The main character's name is Al. He's trying to save a factory that's been underproducing. Al's just discovered that the heat-treat step, which bottlenecks the entire plant, has regular downtime between runs.
        • The Goal p188 excerpt


          "Al, the trouble is there is nothing for the guys down there to do while heat-treat is cookin' the parts. You load up one of the damn furnaces, shut the doors, and that's it for six or eight hours, or however long it takes. What are they supposed to do? Stand around and twiddle their thumbs?"

          "I don't care what they do between times as long as they get the parts in and out of the furnace pronto," I say. "We could have done almost another batch of parts in the five hours of waiting for people to finish what they were doing elsewhere and change loads."

          "All right," says Bob. "How about this: we loan the people to other areas while the parts cook, but as soon as the time is up, we make sure we call them back immediately so—"

          "No, because what is going to happen is everybody will be very conscientious about it for two days, and then it'll slip back to the way it is now," I say. "I want people at those furnaces standing by, ready to load and unload twenty-four hours a day, seven days a week.

          [...]

          "You bet," says Bob. "But you know you're taking about two, maybe three people per shift."

          "Is that all?" I ask. "Don't you remember what lost time on a bottleneck costs us?"

        • Note the love/hate relationship in full force.
          • Slack almost everywhere is great
          • But we never want slack at the bottleneck ever
          • That means the people at the bottleneck do less work than anyone else(!)
          • But we run three shifts, which means people working through the night
        • You can see that in this way of thinking the expected human toil depends entirely on what the bottleneck is like. In this case it's reasonably pleasant, but it could be very bad.
        • Also note that viewing this from an efficiency lens doesn't require reading between the lines. It's explicitly stated on p.194:
          • I sit there marveling that we're going to reduce the efficiency of some operations and make the entire plant more productive. They'd never believe it on the fifteenth floor.

      • ⚛️
        SpaceX optimizes for cost efficiency, not performance efficiency


        • reddit comment link
          • SpaceX has a different design philosophy than most other launch providers. Most launch providers optimize for performance efficiency, SpaceX optimizes for cost efficiency.

            example:

            The Ariane 5 uses different engines for their first and second stages while the Falcon 9 uses the same engines for their first and second stage. Using different engines for the lower and upper stages is pretty standard among launchers because having one engine designed to operate in the lower atmosphere and one engine designed to operate in the upper atmosphere/vacuum leads to better performance and is one of the reasons the Ariane 5 high performance delivering payloads to GTO relative to the Falcon 9. However, from a manufacturing perspective it is much more expensive to build two different engines than it is to just use one type of engine which is part of the reason a Falcon 9 launch is around three times cheaper than an Ariane 5 launch.

        • note to self: look for more sources for this
    • It leads you to underspend resources
      • 🖊️
        The Rickover Effect - efficiency isn't the objective, effectiveness is


        "[...] But Admiral, all this emphasis on personnel and training is a terrific drain on us. You wouldn't believe how much time goes into it. It just isn't efficient use of all this high-powered technical talent you've recruited. Not to mention your own time".

        "Efficiency isn't the objective, Dunford, effectiveness is. Don't confuse effectiveness with efficiency. I'm convinced that the only way to be effective, to make a difference in the real world, is to put ten times as much effort into everything as anyone else thinks is reasonable. It doesn't leave time for golf or cocktails, but it gets things done."

    • It makes you focus on short-term or measurable things
  • More famous people quotes
    • 👤 Peter Drucker
      • It is fundamentally the confusion between effectiveness and efficiency that stands between doing the right things and doing things right. There is surely nothing quite so useless as doing with great efficiency what should not be done at all.

      • from Managing for Business Effectiveness p. 53–60
  • Math finds efficiency suspicious
    • Models aren't the real world, but it's interesting that the efficiency/redundancy tradeoff shows up in graph theory 101. minimum spanning trees are the most efficient ways to connect every node in a graph, but they're also the most fragile since removing any edge causes the network to split.

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