Client: Larkfield Transit, the city's bus operator.
Question: the mayor has $5 million to make bus rides faster. Which projects should the city fund?
What you have: two candidate projects, their costs, how much time each saves per trip, and how many trips and riders each affects.
Done looks like: a metric that fits the goal, both options compared on it, a fairness check, and a recommendation within budget. All figures are fictional.
Public sector cases have no profit to maximize. The work is the same, but you start by agreeing the metric: what does success mean for the residents?
- Pick a metric that matches the goal. For trip times, passenger-minutes saved (minutes saved per trip × riders on those trips) counts both the saving and how many people get it.
- Compare options per dollar, since the budget is fixed.
- Check fairness and side effects: who benefits, and is anyone left out?
- Fit the plan to the budget.
The trap is optimizing a number the client doesn't care about, such as fare revenue, because it's easy to measure.