* This story is featured in BBC Future’s “Best of 2019” collection. Discover more of our picks.

It’s not easy to accurately predict what humans want and when they will want it. We’re demanding creatures, expecting the world to deliver speedy solutions to our increasingly complex and diverse modern-day problems.

Over the last few decades, researchers have developed a range of pretty effective mathematical solutions that can allocate resources across a variety of industries and scenarios so they can attempt to keep up with the daily demands our lives place on them. But when an allocation made at one time affects subsequent allocations, the problem becomes dynamic, and the passing of time must be considered as part of the equation. This throws a mathematical spanner in the works, requiring these solutions to now take into account the changing and uncertain nature of the real world.

You might also like:

• What’s the 3.5% rule of revolutions?

• How to transform society’s view of time

• Why the internet is breaking up

Such problems are collectively known as dynamic resource allocation problems. They crop up anywhere you find a limited resource that needs to be assigned in real time. (Read about how a violent attack turned one man into a maths genius.)

Whether you’re waiting for a taxi or a next-day delivery, the list of dynamic resource allocation problems and their everyday applications is “almost endless” according to Warren Powell, an engineer at Princeton University who has been investigating these problems since the 1980s.