When to add a dependency
A dependency records that one piece of work depends on another. The classic example is "don't start the first fix until the roof is on" — but you'll find them everywhere on a real job.
Reach for dependencies when:
- One trade has to follow another in a particular order
- A waiting period (concrete curing, paint drying, an inspection) sits between two pieces of work
- A handover or sign-off has to happen before the next stage can start
- You want a visual reminder on the Gantt of how work flows together
Project Commander draws every dependency as a connecting line on the Gantt chart, so once you've set them up you can see at a glance how the schedule fits together.
Adding a dependency
Dependencies are managed from the Dependencies tab on the Work Package detail page.
- 1
Open the Work Package that should depend on another (the one that needs to wait — the successor).
- 2
Click the Dependencies tab.
- 3
Click Add Dependency.
- 4
Search for the Work Package or sub-package it should depend on (the one that has to happen first — the predecessor) by name or number.
- 5
Pick the Dependency Type that matches the relationship. The four options are:
- Finish-to-Start — the successor can't start until the predecessor finishes (this is the most common type by a long way)
- Start-to-Start — the successor can't start until the predecessor starts
- Finish-to-Finish — the successor can't finish until the predecessor finishes
- Start-to-Finish — the successor can't finish until the predecessor starts
- 6
If there's a waiting period or overlap, enter Lag Days — a positive number to delay the successor, or a negative number to let it overlap with the predecessor.
- 7
Click Add. The dependency appears on the tab and a connecting line is drawn on the Gantt.
Linking Work Packages and sub-packages together
Dependencies aren't restricted to Work Packages — you can link any combination:
- A Work Package depending on another Work Package
- A Work Package depending on a sub-package
- A sub-package depending on another sub-package
- A sub-package depending on a Work Package
This lets you model real-world handovers without needing to invent dummy parents. For example, you can say that a single sub-package — the inspection — has to finish before the next Work Package's first sub-package can start.
Lag days in practice
Lag days are how you encode waiting periods or overlaps:
- Concrete curing — a finish-to-start dependency with 7 lag days means the successor starts a week after the predecessor finishes
- Acceleration — a finish-to-start dependency with −3 lag days lets the successor start three days before the predecessor finishes (a negative lag is sometimes called a "lead")
Use whichever number genuinely reflects the work — Project Commander will show the gap or overlap clearly on the Gantt.
Removing a dependency
On the Dependencies tab, every dependency row has a remove button. Click it to break the link. This only removes the connection — neither the predecessor nor the successor is touched.
What you'll see on the Gantt
Once a dependency is set up, you'll see a connecting line drawn between the two bars on the Gantt chart. The direction of the line follows the dependency type — a finish-to-start link runs from the end of the predecessor bar to the start of the successor bar.
If you reschedule a predecessor, the line stays connected and you can see at a glance whether there's now an overlap or a gap. Project Commander doesn't move the successor for you automatically — dependencies are there to inform your decisions, not to enforce the schedule. That keeps you in control of the dates.
Real-world examples
- Roof before first fix — finish-to-start with no lag, so the first fix starts the day after the roof finishes
- Floor screed curing — finish-to-start with 7 lag days between the screed pour and the next trade walking on it
- Two trades running in parallel — start-to-start, so the dryliners and the M&E first fix can both kick off at the same time
- Inspection blocks the next phase — link the inspection sub-package as a predecessor to the first sub-package of the following Work Package
Next steps
- Gantt view — for the full Gantt walkthrough including the dependency lines.
- Scheduling and rescheduling — for drag-to-reschedule and the date-adjustment dialog.
- Sub-packages — for the actions menu including Create Child.