The car rental case

A threefold design exercise

Alberto Romero
Aug 16, 2018 · 2 min read

My friend Gorriti’s favorite cocktail is the Negroni, a simple mix that’s ideal before dinner and not so great after that other Negroni I just had.

I have to admit it has grown on me, and its recipe is the easiest to memorize: stir a mix of gin, vermouth and Campari using a 1:1:1 ratio, then serve on the rocks with an orange peel.


A recent trip to Spain provided the perfect context for an exercise that mixes service, business and interaction design with the same 1:1:1 ratio.

Feel free to use it in class with your students, with apprentices at work, or just use parts of it yourself to practice areas of design you’d like to get better at.

The prompt

Alberto rented a car for five days. On day three, he decides he would like to extend the rental, and return the car at a different location.

He calls the agency, and he is informed of the company policy to do such changes: they do not have a system to change contracts remotely, so customers are required to drive to one of the branches to sign on the new terms.

Alberto is willing to pay the extra fees derived of the new rental, but he is on the road, and driving three hundred miles to do some paperwork seems a bit painful.

Service design exercise

Imagine what the ideal experience for extending a rental and changing the drop-off location would look like. Think of Alberto’s actions, and the exchange of data between him and the agency that could happen through different channels.

Then think about the systems that need to be in place for that experience to happen, and how removing friction from the driver increases the required sophistication of those systems. Define what Alberto must do and see, and what should just happen behind the scenes.

Interaction design exercise

Chances are you have come up with some kind of phone conversation, or a new feature to go on the company’s website or mobile app. Now design how that interaction happens.

Think about flows, capturing data and providing feedback. Design the user interfaces for each step. Try to imagine how the new piece fits in the whole, and what existing patterns you should be matching.

Business design exercise

Understand the company’s business model, and then go back to the prompt. Try to identify where this need is taking place, how it affects the relationship with a customer and where is the potential value, both from a revenue and customer development point of view.

Take your designs and try to estimate the cost of implementing different versions of the solution. Compare it with the benefits of implementing it. Think about the risks of the different options, and think also about the risks of not making a decision.

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