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.