A 100-Day Challenge is a rapid, structured project designed to make significant progress on a complex strategic issue. It is not “business as usual.” It is a journey for frontline teams and leaders from different organisations to collaborate across silos, experiment with new ideas, and deliver tangible results in just 100 days. So why are they different from traditional projects that last 100 days? And why do we believe that they enable unusually high levels of performance in teams and organisations?