Work with the project scheduler to update the project timeline. The project manager should work with the project scheduler to update the project timeline after finding an unforeseen dependency on one of the critical project activities that will most likely cause a delay. The project scheduler is a person or a tool that helps plan, schedule, monitor, and control the project activities and resources. The project scheduler can help the project manager to assess the impact of the dependency on the project schedule and identify any possible ways to mitigate or resolve it. The project scheduler can also help to update the project timeline with the revised dates and durations of the project activities and communicate them to the relevant stakeholders.