Elicit trade off between two variables

The line drawn on a two variable tradespace between all the non dominated options

Every dot is a valid feasible design

Our intuition may be worse on important problems; certainly no reason to believe they are positively correlated

the most impactful decisions that produce different architectures

tend to be mutually exclusive

controllable

ie my idea of a design choice

a decision within the control of the creator of a system

upstream of metrics

e.g. can’t dictate a “reliability” metric

Exercise on a system

Glider architectural decisions

Engine

Passenger capacity

Wing type

Wing position

Landing gear configuration

Material

tests for architectural decisions

1

sensitivity

changing x significantly changes system outcomes

connectivity

harder to change later because there is a lot of interdependence

Is connectivity actually different than cost ?

Good architectural decisions are like finding the end of the ball of yarn

it makes a lot of decisions with one decision

High sensitivity and high connectivity decisions should be made earlier and with more care