Unlocking engineering expertise frozen by grand challenges: dealing with transitions' unknown

The contemporary transition of climate change, technology evolution, and social inequality present profound challenges in project management. It requires multitude of stakeholders who are facing many unknowns on the solution to develop. This study explores how grand challenges impact the nature of unknowns encountered by engineering actors in project management. Through a historical analysis of innovation projects within a century-old automotive manufacturer, we identify distinct types of unknowns—desirable, undesirable, endogenous, and exogenous—and examine the processes required to manage them, including endogenization and desirabilization. We demonstrate that the unknowns generated by grand challenges represent a densification and complexity beyond those traditionally managed, necessitating new knowledge management processes. From a scientific perspective, this research enriches the understanding of unknowns in design activities and adapts this concept to the context of grand challenges. From a practical perspective, it provides actionable insights for engineering departments to address these unknowns independently, without relying on systemic coordination.