Start-to-Finish in Primavera: The Ultimate Beginner’s Guide to Smart Project Scheduling
New planners often find Primavera project scheduling confusing because it works opposite to the flow of most scheduling relationships. Most links in a project plan follow a natural sequence, where one task ends and drives the start of another. However, Start-to-Finish flips this logic. It creates a unique condition where a successor cannot finish until its predecessor starts. This reverse dependency leaves many beginners unsure about when or how to use it.
Despite the confusion, Start-to-Finish is a powerful tool. It supports real-world situations where one activity must continue until another begins. This relationship is not only valid but essential for accurate modeling of continuous operations, handovers, and transitions. Without it, some schedules become unrealistic, disconnected, or inaccurate. Planners often patch such gaps with hard constraints, which later distort the timeline.
Primavera project scheduling
Understanding Start-to-Finish helps you build schedules that reflect actual site workflows. It also improves coordination between teams, enhances risk visibility, and creates seamless sequencing. This guide is designed to help beginners understand the logic, apply it step-by-step, and use it with confidence.
By the end of this article, you will know when Start-to-Finish is essential, how it affects dates, how to apply leads and lags, and how to avoid common modeling mistakes. You will gain clarity through real-world examples, practical guidance, and best practices used by professionals. Let’s begin by breaking down the meaning and purpose of this relationship.
1. Understanding the Start-to-Finish Relationship
The Primavera project scheduling relationship defines a dependency where the predecessor must start before the successor can finish. This means the completion of the successor is directly dependent on the beginning of the predecessor. It is the reverse of the most common Finish-to-Start relationship. Because of this reversed logic, many users hesitate to include it in their schedules.
To understand the relationship better, imagine two activities:
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Activity A – Predecessor
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Activity B – Successor
With a Start-to-Finish relationship, Activity B cannot finish until Activity A starts. The beginning of Activity A unlocks the end of Activity B. While this sounds backward at first, it fits many operations where continuity must be maintained until a new phase begins.
This relationship helps project planners reflect dependencies that do not follow a simple linear sequence. It models conditions where an ongoing task must stay active until another team or resource begins work. For example, in shift scheduling, the night shift cannot finish until the morning shift starts. In security operations, temporary guards cannot leave until the permanent staff arrives.
Another important detail is how Primavera calculates the dates. When you apply a Start-to-Finish dependency, Primavera will shift the successor’s finish to align with the predecessor’s start. This ensures the successor remains open until the controlling activity begins. This adjustment creates a realistic flow that mirrors on-ground processes.
While it is rarely used compared to Finish-to-Start or Start-to-Start, Start-to-Finish is far from unnecessary. It is essential for modeling specialized workflow transitions. Without this relationship, planners might use fixed constraints that make schedules rigid or inaccurate.
Start-to-Finish works best when the finish of an activity must wait for the start of another. If this logic fits your scenario, then this relationship provides unmatched accuracy.
2. When and Why Start-to-Finish Is the Best Choice
Although Primavera project scheduling is not used frequently, it becomes the ideal choice in scenarios requiring continuity or smooth transitions. Its purpose is not to complicate planning but to handle situations where traditional relationships fail to reflect real operations.
Here are the most common situations that require a Start-to-Finish relationship:
Shift Transition Scenarios
Shift work is the classic example. One team cannot leave until another team arrives. If the incoming shift gets delayed, the outgoing shift must stay. This ensures there is no absence of coverage. Start-to-Finish models this dependency perfectly. It prevents gaps in the schedule and helps planners understand staffing risks.
Security and Operational Continuity
Security teams rely heavily on Start-to-Finish relationships. A temporary security detail must remain on-site until the permanent team begins. If guards leave before their replacement arrives, it creates a security breach. The Start-to-Finish link ensures such situations never appear in the schedule.
System Transitions and IT Cutovers
In IT projects, old systems often remain active until the new system goes live. The old system cannot shut down until the new system starts. This protects data flow, user access, and continuity of operations. A Start-to-Finish relationship helps accurately reflect this handover.
Logistics and Production
Consider unloading operations. A team unloading shipments cannot complete their task until the receiving team begins processing materials. This ensures no goods are left unattended or exposed. The Start-to-Finish relationship creates a clean, safe handover.
Maintenance and Equipment Swaps
Old equipment often stays operational until the replacement installation begins. For example, an old pump runs until the new pump installation team starts their task. The Start-to-Finish relationship helps represent this dependency clearly.
Why This Relationship Matters
When used correctly, Start-to-Finish keeps schedules realistic. It prevents premature finish dates, eliminates unrealistic gaps, and supports operational integrity. While many schedulers avoid it due to lack of understanding, those who use it gain better accuracy and control. It solves a unique scheduling challenge that cannot be managed well through other links.
3. How to Apply Start-to-Finish in Primavera Step by Step
Once you understand the logic, applying Start-to-Finish in Primavera becomes simple and intuitive. Primavera P6 makes the process easy. The key is knowing when to use it and ensuring your logic aligns with real-world workflows.
Follow the steps below:
Step 1: Identify the Successor
The successor is the activity that cannot finish until another activity starts. Select this activity first. This could be a shift ending, unloading process, or temporary support task.
Step 2: Open the Relationships Window
Right-click on the successor and choose “Relationships.” This opens a window where you can add predecessors or successors.
Step 3: Add the Predecessor
Click “Add.” Then choose the activity whose start will drive the finish of your selected activity.
Step 4: Select the Relationship Type
From the relationship options, pick Start-to-Finish (SF). Primavera will now understand that the successor’s finish depends on the predecessor’s start.
Step 5: Adjust Leads or Lags if Needed
You can add a lag if there is a delay between the start of the predecessor and the finish of the successor. For example, if the night shift hands over 30 minutes after the morning shift starts, you can add a 0.5-hour lag.
Step 6: Run the Schedule
After linking the activities, click “Schedule” to recalculate. Primavera adjusts the dates to match the new relationship.
Step 7: Check Calendars and Constraints
Ensure both activities use appropriate calendars. Misaligned calendars can shift dates unexpectedly. Also review constraints to make sure they do not override logic.
Step 8: Review Network Logic
Check the overall schedule to confirm the relationship supports workflow and does not create circular logic or conflicts.
By following these steps, beginners can confidently apply Start-to-Finish logic without confusion.
4. Real-World Examples That Make Start-to-Finish Easy to Understand
Understanding Start-to-Finish in Primavera becomes easier when paired with real examples. Below are detailed scenarios that show the relationship in action and explain its purpose clearly.
Example 1: Shift Handover
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Predecessor: Morning shift
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Successor: Night shift
The night shift cannot finish until the morning shift starts. If the morning team is delayed, the night team stays longer. A Start-to-Finish link captures this dependency without manual adjustments.
Example 2: Security Team Replacement
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Predecessor: Main security team starts
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Successor: Temporary guards finish
Temporary guards must stay until permanent staff arrives. This ensures continuous security coverage. Without this relationship, the schedule may show a dangerous gap.
Example 3: IT Cutover
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Predecessor: New system activation
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Successor: Old system shutdown
The old system stays active until the new one goes live. If activation gets delayed, the existing system continues operating. Start-to-Finish models the transition.
Example 4: Equipment Swap in Industrial Plants
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Predecessor: New equipment installation
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Successor: Old equipment decommissioning
The old equipment must operate until installation begins. A Start-to-Finish relationship ensures the schedule reflects this dependency accurately.
Example 5: Logistics Handling
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Predecessor: Receiving team starts
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Successor: Unloading team finishes
Unloading must not finish until receiving begins. This prevents materials from being left unattended. The relationship ensures a smooth handover.
These examples demonstrate how Start-to-Finish mirrors real-world interactions between teams and processes. When used in the right situations, it enhances schedule realism, continuity, and operational flow.
5. Common Mistakes and How to Avoid Them
While Start-to-Finish in Primavera is powerful, beginners often misuse it due to misunderstanding. Avoid these mistakes to maintain schedule quality and accuracy.
Mistake 1: Using SF When FS Is Enough
Many planners choose Start-to-Finish because they think it is advanced. But if a simple Finish-to-Start relationship works, don’t complicate logic. Use Start-to-Finish only when the finish must depend on the start.
Mistake 2: Ignoring Calendar Variations
If the predecessor and successor use different calendars, Primavera may produce unexpected dates. Always verify working hours, holidays, and shifts before linking activities.
Mistake 3: Adding Excessive Lag
Lags help, but too many lags complicate schedules. Only use lag where logic requires it. Manual offsets can make schedules confusing and difficult to explain.
Mistake 4: Creating Circular Logic
Circular logic happens when tasks depend on each other in a loop. Primavera alerts you, but prevention is better. Ensure each relationship reflects real workflow direction.
Mistake 5: Not Reviewing Network Impact
A Start-to-Finish relationship may shift multiple downstream dates. Always run a schedule review after adding SF links. This ensures your schedule remains stable, readable, and accurate.
By avoiding these mistakes, planners ensure clarity, consistency, and correctness in their scheduling logic.
Conclusion: Master Start-to-Finish, Strengthen Your Entire Schedule
The Primavera project scheduling relationship may seem unusual at first, but once you understand its purpose, it becomes a critical tool in advanced scheduling. It helps planners manage transitions, ensure continuity, and reflect real-world constraints more accurately than any other relationship type. With the step-by-step guidance, examples, and best practices shared in this guide, beginners can now apply Start-to-Finish with confidence and clarity.
This knowledge not only improves your Primavera skills but also enhances your ability to model complex project scenarios. When used wisely, Start-to-Finish relationships strengthen the entire schedule and create a more reliable project plan.
