Define Activity Dependencies
Explanation
Use this activity to define dependencies between existing activities,
which are essential for scheduling calculations. Dependencies establish
logical relationships between activities, such as predecessor/successor
links, creating an activity network. This network serves as a key input for
scheduling calculations performed in tools like the Project
Scheduler or Project Gantt. By defining
dependencies, you ensure that the project schedule reflects the planned activity
sequencing, enhancing accuracy and efficiency in planning. Having an
activity network also allows for effective management of changes, as
rescheduling will take all dependent activities into account.
In the application, select a dependency to a predecessor or successor
from the available options.
Dependency Types
Dependencies can be defined using the following types:
- Finish-to-Start (FS)
The most common type of
dependency. The successor activity cannot start until the predecessor
activity finishes.
Example: Activity A1 (Predecessor) must
finish before Activity A2 (Successor) can start. - Finish-to-Finish (FF)
The successor activity
cannot finish until the predecessor activity finishes.
Example:
Activity A1 (Predecessor) must finish before Activity A2 (Successor) can
finish. Both activities may be in progress at the same time, but A2
cannot be completed until A1 is completed. - Start-to-Start (SS)
The successor activity
cannot start until the predecessor activity starts.
Example:
Activity A1 (Predecessor) must start before Activity A2 (Successor) can
start. Both activities may continue independently after they start. - Start-to-Finish (SF)
The successor activity
cannot finish until the predecessor activity starts.
Example:
Activity A1 (Predecessor) must start before Activity A2 (Successor) can
finish. This is the least common and often used in specific scenarios
like shift handovers.
Prerequisites
- Activities must already exist in the project.
System Effects
As a result of this activity:
- Logical dependencies are established between activities, forming an
activity network.
- The system uses this network in project scheduling to:
- Calculate the critical path, identifying which activities
directly affect the project’s end date.
- Determine float/slack, helping identify which activities have
scheduling flexibility.
- Ensure dependent activities are updated during rescheduling, so
when one activity is changed, all linked activities are adjusted
accordingly.
- Support impact analysis, making it easier to assess how delays
or changes affect the overall project timeline.