Every day operations managers face decisions, some simple and some complex. Our text focuses on these decisions with real world examples and hundreds of mathematical models to help guide decision making. But all too often students look for “the answer” on a search engine (or now on ChatGPT), learning nothing from the process.
Prof. Larson’s innovative approach to model thinking encourages:
- Active learning with pencil and paper (no computer), which requires readers to immerse themselves in puzzles and life’s paradoxes.
- No heavy math – complex technical issues are addressed in a simple, entertaining way.
- Seeing the world in terms of models, learning something new every day.
Here is an example: Suppose you need to be on today’s only ferry to Martha’s Vineyard, which leaves at 2 p.m. It takes about 30 minutes (on average) to drive from where you are to the terminal. What time should you leave?
In this example, a key concept at play is uncertainty. Accounting for uncertainty is a core challenge faced by operations managers. We need to see that:
- an average of 30 minutes would cover a range of times, some shorter, some longer;
- outliers can exist in the data, like the time construction traffic added an additional 30 minutes
- “about 30 minutes” is a prediction based on past experience, not current information (road closures, accidents, etc.); and
- the consequence for missing the ferry is not a delay of hours, but a full day — which might completely disrupt the trip or its purpose.
Without doing much math, we calculate variables, weigh the likelihood of different outcomes against the consequences of failure, and choose a departure time. Larson’s conclusion is one championed by model thinkers everywhere: Leave on the earlier side, just in case.
“Everybody uses models, whether they realize it or not,” Larson says. “When someone is shopping for groceries and thinking about how much of each product they need — they’re basically using an inventory management model of their pantry.”