Teaching Operations Research with food

26 January 2012
Effective multimedia teaching videos
10 February 2012

Food is a universal context

Food is a universal context

What I like about Operations Research is its applied nature. It is mathematical and useful. We need to make sure that our students recognize that. As students have often had little experience in the world of business and manufacturing, it can be helpful to use examples based around food. Food is a universal topic. We all need food and most of us enjoy it and probably eat too much. For this reason food is a useful context to use in teaching.

Linear programming diet problems

The linear programming diet problem is an obvious starting place. For decades linear programs have been used to find optimal combinations of different types of feed for animals such as pigs, cattle and poultry. A popular teaching diet problem is based on McDonald’s fast food. Information on nutritional content and requirements is easily sourced these days on the web. Students can create their own diet problems and find the least cost solution to feed themselves a minimum cost, balanced (within reason) diet at McDonalds. When we used this as a student assignment the solution involved a large number of soft-serve ice cream cones. This sort of solution helps teach students that the computer finds the optimal solution to the model, which may not be even feasible in reality, if there are too many implicit constraints.
A popular variation of the McDonalds diet problem was the Hiking diet problem. This was a little different as the objective was minimising weight rather than cost. Again the initial “optimal” solution lacked variety. (This gave us the opportunity to teach that the number of non-zero variables at optimality will not exceed the number of binding constraints.) The students enjoyed the assignment and some were inspired to the extent that they used it to cater for a hike. Another example was refugee boxes, aiming to provide a balanced diet for a family for a week, at minimum cost.In all these examples the problem of non-integer solutions can also be addressed.

Other Operations Research topics can be taught using food.

When teaching about fixed and variable costs, and developing a spreadsheet model, our example is that of a sausage sizzle. In it the students are setting up to sell sausages wrapped in bread, with onions, cooked on a barbecue. The aim is to find the breakeven point.
Critical path can be taught in the context of planning a three course dinner.

Many examples are built around Choconutties

I have been accused of making everything about food. Our series of videos for teaching statistics and spreadsheet modelling centre around Helen, who sells choconutties. In our test and practice examples we have bakeries, candy manufacturers, jam-makers and cafes. Food examples are used for inventory control, break-even analysis, linear programming, decision analysis and critical path.
Students need to be engaged with the material, and it helps if the examples and contexts are familiar. There is a case for using business examples as well, as these help develop their understanding of business and its vocabulary. But food is a good place to start.