P6 Professional features a comment tool to clarify one of the most abstract elements of a schedule: relationships.
An important attribute of quality schedules is transparency. Schedules should be understood by all stakeholders. Like good computer code, a schedule needs to be well-documented. P6 Professional satisfies this need with relationship comments, a feature for individual relationships.
Typically, logic links lack transparency, appearing as simple lines between tasks without labels or context. The relationship comments tool allows schedulers to explain a link’s purpose or note technical specifications.
While viewing these relationship comments requires P6 access, meaning some stakeholders cannot easily see them, the feature provides invaluable documentation for managers tracking minute project details.
This article explains how to view and relationship comments in P6 Professional.
How to view Relationship Comments
We want to review comments on the Finish-to-Start (FS) relationship between Insulate Piping and Write Quality Assurance Report. Follow these steps to confirm whether this FS relationship has any additional important project information associated with it. Choose Activities | Relationships > Successor frame and right-click (star stamp number 1) on any header for the successor frame.
In the pop-up Successor Columns dialog box, navigate to the General category, select Comments, and click the right arrow to include Comments in the Selected Options.
Figure 3 displays the schedule highlighting the Insulate Piping task, displaying Relationships in the bottom details, and the Successors frame, which now has a Comments field.
The comment confirms that striking the forms should be done before completing the pipe insulation to ensure a snug fit of the insulation at the pipe-and-thrust-block interface. It would also be helpful to add a Comments field to the Predecessors selected options.
How to insert Relationship Comments
Adding a comment is as easy as viewing the comment field and typing in your relationship-related information. In Figure 4, we are in the Activities tab, with Concrete Inspection selected in the activities table and Relationships tab selected in the bottom details.
When reviewing the Successor frame, we see an empty comment field. First note that the comment field that we previously added will now always be included in the bottom details Relationships tab Successors frame selected columns. Second, in Figure 4, adding a comment is as easy as selecting the Comments field and typing in your documentation. Figure 5 displays the schedule, with a comment on the FS relationship that connects Concrete Inspection to Strike Forms.
To ensure your notes provide real value during an audit, focus on these key elements:
Say why, not what
The link already shows the sequence. Your comment should explain the reason behind it. “Concrete curing per spec section 03300, 28 days minimum before formwork removal” is more helpful than “B follows A.”
Reference your sources
If a dependency comes from a spec, a contract or a drawing, say so. Something like “Per IFC drawing rev C, 15-Mar-2026” gives anyone reading it a paper trail to follow.
Flag your assumptions
If a relationship is based on a planning assumption rather than a hard constraint, call it out. Try something like: “Assumes single crew – revisit if crew is split across zones.” This is most useful when conditions change on-site.
Know the difference between hard and soft logic
Hard logic means one thing: physically, one thing cannot happen before another. Soft logic is more of a preference or resource call. Noting which type you’re dealing with will help everyone understand how much flexibility exists in the schedule.
Keep them current
If you change a relationship during the project, update the comment too. A comment that contradicts the current logic is worse than no comment at all.
Some Real-World Examples
| Situation | What the comment might say |
| Permit dependency | Cannot start excavation until the earthworks permit is issued by the local authority |
| Contract milestone | Tied to Section 5.3 milestone — early completion triggers bonus clause |
| Shared resource | Delayed start — crane shared with Zone B; only one lift crew available |
| Design approval | Structural design must be approved before long-lead steel procurement begins |
| Safety sequence | Hot work cannot start until fireproofing in the adjacent area is complete and signed off |
Relationship Comments vs. Activity Notes – what’s the difference?
| Relationship Comments | Activity Notes | |
| Attached to | The link between two activities | A single activity |
| Purpose | Explains the dependency logic | Describes the activity itself |
| Best used for | Why is this link here? | What does this activity involve? |
One more thing: Claims and Forensic Analysis
If your project ever faces a dispute or delay analysis, relationship comments can make a significant difference. They prove that the schedule logic was deliberate and documented, rather than arbitrary. This clear, contemporaneous evidence holds up far better than attempting to recollect your reasoning years after the fact.
Summary
A well-commented schedule is a sign of a mature, professional scheduler, saving everyone time and frustration. Relationship comments are strategically located in the Activities tab | bottom details.
While you can add text boxes directly to the Gantt chart, this is not recommended. The Gantt chart is the heart of your scheduling software, and cluttering it obscures the logic of your network diagram. You can print a comment with a printed report. However, the bottom-details Relationships tab is the most efficient way to review a relationship’s critical notes.