Predecessor Task in Microsoft Project
A Predecessor Task is a task that must happen before another task can start or finish.
In simple words:
👉 Predecessor = Previous Task
👉 Successor = Next Task
Think of it like a chain:
Task A → Task B → Task C
Task A is the predecessor of Task B.
Task B is the successor of Task A.
Task B is the predecessor of Task C.
Why Predecessor Tasks Are Important
Predecessor tasks help Microsoft Project:
Calculate start and finish dates automatically.
Create logical work sequences.
Prevent tasks from starting too early.
Build accurate project schedules.
Identify the critical path.
Without predecessors, all tasks are independent, and the schedule may become unrealistic.
Construction Example
| ID | Task | Duration | Predecessor |
|---|---|---|---|
| 1 | Site Clearing | 2 Days | - |
| 2 | Excavation | 3 Days | 1 |
| 3 | Foundation Concrete | 5 Days | 2 |
| 4 | Column Construction | 4 Days | 3 |
This means:
Complete Site Clearing.
Then start Excavation.
Then start Foundation Concrete.
Then start Column Construction.
Microsoft Project automatically links these activities.
Common Relationship Types
1. Finish-to-Start (FS) — Most Common
Task A must finish before Task B starts.
Example:
Excavation → Foundation Concrete
Excavation (Finish)
↓
Foundation (Start)
2. Start-to-Start (SS)
Both tasks start together.
Example:
Ceiling Work
Electrical Installation
When ceiling work starts, electrical installation can also start.
3. Finish-to-Finish (FF)
Both tasks must finish together.
Example:
Testing
Documentation
Documentation cannot finish until testing is completed.
4. Start-to-Finish (SF)
A rare relationship.
Example:
Old Security Guard
New Security Guard
The old guard cannot finish his shift until the new guard starts.
How to Enter a Predecessor
Method 1: Predecessors Column
Create your task list.
Find the Predecessors column.
Enter the ID number of the predecessor task.
Example:
| ID | Task | Predecessor |
|---|---|---|
| 1 | Foundation | |
| 2 | Columns | 1 |
| 3 | Beam | 2 |
Method 2: Link Tasks Button
Select two tasks.
Click Link Tasks (chain icon).
Microsoft Project creates an FS relationship automatically.
Example for House Construction
| ID | Task | Duration | Predecessor |
|---|---|---|---|
| 1 | Site Preparation | 2d | |
| 2 | Excavation | 3d | 1 |
| 3 | Footing Concrete | 2d | 2 |
| 4 | Foundation Wall | 4d | 3 |
| 5 | Ground Floor Slab | 3d | 4 |
| 6 | Columns | 4d | 5 |
| 7 | Beams | 4d | 6 |
| 8 | Roof Structure | 5d | 7 |
Each task depends on the previous task.
Best Practice
✅ Always define predecessors for every major task.
✅ Use FS relationships by default unless another relationship is needed.
✅ Review predecessors regularly when updating schedules.
✅ Avoid creating too many unnecessary links.
✅ Make sure the logic matches actual construction work.
Simple Formula to Remember
Predecessor = "What must happen before this task?"
When creating a schedule, ask yourself:
"What task must be completed before this task can begin?"
The answer is the Predecessor Task.
Easy Construction Example
Question: What must happen before "Brick Wall Construction" starts?
Answer: "Column and Beam Construction" must be completed.
Therefore:
Column and Beam Construction = Predecessor
Brick Wall Construction = Successor
This simple question helps you build a logical and professional schedule in Microsoft Project.