What are some examples of dummy activities in project management and how do they impact the overall project timeline?

Dummy activities in project management are tasks that do not contribute to the project's progress but are included to maintain the logical sequence of activities. Examples include waiting for approvals or dependencies on other tasks. These activities can impact the project timeline by causing delays or creating bottlenecks, as they may hold up critical tasks from starting or completing on time. It is important for project managers to identify and minimize dummy activities to ensure efficient project execution.