Finish-to-Start (FS)

Finish-to-Start (FS) is a logical relationship in which a successor activity cannot start until a predecessor activity has finished. This is the most common dependency type in project scheduling.

Key Aspects of Finish-to-Start

• Successor Activity Cannot Begin Until the Predecessor Is Complete – Ensures sequential task execution.
• Most Common Logical Relationship – Frequently used in project planning and scheduling.
• Helps Define Project Workflows – Critical for scheduling dependencies and determining task order.

Finish-to-Start vs. Other Logical Relationships

Dependency Type	Definition	Example
Finish-to-Start (FS)	Successor cannot start until predecessor finishes.	Construction painting cannot begin until wall installation is complete.
Finish-to-Finish (FF)	Successor cannot finish until predecessor finishes.	Proofreading cannot finish until writing is complete.
Start-to-Start (SS)	Successor cannot start until predecessor starts.	Framing a house cannot start until foundation pouring begins.
Start-to-Finish (SF)	Successor cannot finish until predecessor starts.	The night shift cannot finish until the next shift starts.

Example Scenarios

Software Development

A testing phase cannot start until development is fully completed.

Construction Project

A roofing team cannot start work until the building structure is fully assembled.

Marketing Campaign

A social media campaign cannot begin until the graphic design team completes the ad creatives.

Mermaid Diagram: Finish-to-Start Dependency

graph LR;
    A["Task A: Write Report"] -->|Must Finish Before| B["Task B: Submit Report"]
    B -->|Can Only Start After Task A is Done| C["Task C: Publish Report"]

Why Finish-to-Start Matters

• Ensures Logical Task Progression – Maintains correct order of operations.
• Prevents Premature Execution of Tasks – Ensures dependencies are respected.
• Improves Project Scheduling – Helps define clear relationships between tasks.
• Essential for Critical Path Analysis – Used to determine the project’s longest path.

See also: Finish-to-Finish (FF), Start-to-Finish (SF), Start-to-Start (SS), Logical Relationship, Schedule Network Diagram.