Part 5 · 2 chapters · ~12 min

Problems with No Right Answer

Trade-off problems, making constraints and criteria explicit, weighted decision matrices and their sensitivity, satisficing versus optimising, choosing reversible options in close calls, and explaining a decision others disagree with.

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Making the trade-off explicit

Herbert Simon's satisficing (choosing the first option that meets all the requirements) beats optimising when information is costly and the options are close.

A WEIGHTED TRADE-OFF
three designs for letter generation scored against weighted criteria (1-5, weights sum to 100%)
A: synchronous in API3.1B: queue + workers4.2C: third-party service3.4
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no right answer
Some problems have several reasonable answers that trade different goods: latency, cost, risk, simplicity. Pretending one is "correct" hides the trade-off.
several reasonable answersthe trade-off is the content
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Explaining the decision

when people disagree with the choice
  1. Show the criteria and weights, and invite argument there rather than about the conclusion.
  2. Acknowledge what the chosen option gives up ("B is slower to build than A").
  3. State what would make you revisit ("if queue latency exceeds 10 minutes at peak").
  4. Ask for commitment, not agreement: disagree and commit.