Activity Definition Guide: PMBOK 7th Edition
Activity Definition is a critical component of project time management which revolves around the identification and documentation of the specific actions to be performed to deliver project deliverables.
Importance: Without precise activity definition, project scheduling, estimating, controlling, and management could be drastically off track. It creates a clear roadmap for project execution and control, providing the groundwork for the sequence, resources, and durations in the project schedule.
Working: The process involves breaking down work packages into smaller, manageable activities that provide a basis for estimating, scheduling, executing, monitoring, and controlling the project work.
Exam Tips: Expect questions on the exam where you need to differentiate between the 'work package' and 'activity'. Remember, activities are measurable and controllable. In such questions, try to identify the lowest level of work in the scenario - this is typically the 'activity'.
Don't forget: 'Activity definition' is different from 'activity list'. The former is a process whereas the latter is a document resulting from that process. Being aware of this can help answer questions related to these concepts.