In an uncertain environment, it's crucial for a project manager to validate assumptions and assess risks. This involves identifying, evaluating, and controlling uncertain factors that can significantly affect the project's performance1. This process, known as risk management, helps to avoid or mitigate potential negative effects1. It's also important for the project manager to be comfortable with uncertainty and to be able to react to it in an agile, but well-structured way2. This approach gives the project team confidence that the project is still taking the right steps to deliver as planned2. References: 1 Managing Project Uncertainty: From Variation to Chaos, 2 Managing projects in uncertain times - APM