TBH I strongly disagree with OP’s suggestion that 95% reliability is low / bad, at least read literally. I personally definitely fail verbal ‘soft commitments’ (“I expect this will be done by end of week”) with way more than 5% rate; probably more like 20-30. Part of it is being in business where hidden complexity strikes at any time, and estimating is hard; part of it is because of cultural communication norms.
If you ignore soft commitments, then the easy way to improve reliability is to make less hard commitments. Instead of “I’ll definitely be there at 9 am sharp”, say “I’ll do my best to be there at 9 am”. Manage expectations. Then if you have to message them 30 mins before that you’re stuck in traffic / running late, your reliability is not impacted.
For stuff with really hard acceptance criteria (you actually have to be there for 9 am, because the plane won’t wait), the right way to improve reliability is to build fault tolerant systems; make a soft commitment to be there an hour before, or have more people work on a problem than you expect to be necessary.
Yes, this post was very useful as advice to reverse to me. I think it possible now that one of the biggest problems with how I’m living my life today is optimising too hard for slack.
Low-confidence comment disclaimer; while I’ve had the concept pretty much nailed down before, I never before thought about it as something you might have too much off. After reading this post I realised that some people do not have enough slack in their life, implying you can choose to have less or more slack, implying it’s possible too have too much slack.
I don’t have abstract ‘this is what too much slack looks like’ clearly defined right now, but one thing resonates from my own experience. I often find myself with free time, and ‘waste it away’. I don’t really do anything on most weekends. Having more constraints as guidance for behaviour in free time could likely remediate that; but I seem to be very good at talking myself out of any recurrent commitments, saying that they would reduce my freedom/flexibility/slack.
At the same time, it seems to me that I’m happiest, most ‘alive’, most in the ‘flow’, in situations with exactly the kind of binding constraints this post talks of avoiding. The constraints focus you on the present, on the very moment, on being. For me this is clearest in sailing regattas—a clear purpose that acts as a binding constraint (to go as fast as possible while staying safe—a safety margin does not for slack make, since you are not willing to ignore crossing it), consuming all your attention (at least during the time you’re responsible for the ship, and often more).
I suppose one can stretch the metaphor and say that having no slack on too many dimensions is likely to squash you; but having slack everywhere leaves you floating around aimlessly. Keeping most constraints slack and choosing only a couple aligned ones to bind against is possibly a way to find purpose.