search cancel

Autoschedule not honoring dependencies


Article ID: 222814


Updated On:


Clarity PPM SaaS Clarity PPM On Premise


We depend on the Finish to Finish (FF) dependency type with negative lag for project scheduling.  Auto schedule is not honoring the dependencies.  The projects are required to finish on specific days. Why aren't dependencies being honored and what do we need to do to make it work as expected?  What are steps to troubleshoot what is causing the issue?

Steps to Reproduce

  1. Navigate to a project
  2. Open the Gantt
  3. Choose to Autoschedule with options 
  4. Uncheck Resource Constraints and check Subnets - leave Autoschedule Date as current system date
  5. Click Autoschedule 

Expected Results:  Autoschedule honors the dependencies

Actual Results: Dependencies are not honored

Opening the project in Open Workbench (OWB) and using the same settings (except subnet which is not available in OWB) produces the same results.


Release : All Supported



Is the issue a task dependency not updating at all?

If yes, check to see if the task is locked. If yes, unlock it. 

  1. From the Clarity Gantt, add the field "Locked"
  2. If it shows as checked for the task, it means it's locked, so you would want to change the value from Yes to No for the task

Is the dependency not updating to an expected date?

If the issue is the dependency is not updating to an expected date:

Is there a constraint on the task? 

  • If yes, this can impact whether the date gets autosheduled to an expected date or not. Validate that the date set is an expected date, and if not, update the date
  • If no, no constraint can cause it to change to the project start date depending on dependencies and other factors

Is there a lag?

  • If yes, count how many business days to see if it lines up based on that. Example: 
    • Task 1 has a FF dependency with Task 2 and a lag of 85 days and is showing with a Finish date of 12/18/20.
    • If the Finish date of Task 2 is 4/16/21, you can do a test by creating a new task with a start date of Task 1's Finish Date and a Finish Date of Task 2's finish date to see if the duration lines up with the Lag. You can also check the calendar based on business days if uncertain. Example for this task scenario below: 
      • April: 12 Business days (Counting business days before 4/16/21)
      • March: 23 Business Days
      • February: 20 Business Days
      • January: 21 Business Days
      • December: 9 Business Days (after 12/18/20)
      • This totals to 85 days. 

Check the Autoschedule Date

  • If you leave this as the Default (current date) it will update dates based on that date, so remove this date and see if tasks then autoschedule as expected. 

Is the task Fixed Duration? 

  • Having a task set as Fixed can impact how a task is autoscheduled. To prevent durations from changing, check to confirm the task is set to "Fixed". 

To keep the date from changing

  • Another option if you do not want the task to update at all when autoscheduled, is to Lock the task.
  • Adding a constraint can also help. See the steps to do this below:

Add a constraint to a task from within Classic Clarity:

  1. In Classic Clarity, go to Home->Projects then click on the link for the project.
  2. Click on the Tasks tab.
  3. Click on the link for the task.
  4. Select the 'Properties' tab and then click 'Constraints'
  5. Update the date in the Constraints fields based on how you want the task to behave, then click Save and Return.

Add a constraint to a task from Modern UX Clarity:

  1. In Modern User Experience (UX), click on a project then go to the Tasks tab/module
  2. From here, you can add the various recommended constraint types:
    • Start no Earlier Than
    • Must Start On
    • Finish No Earlier Than
    • Must Finish On
  3. Populate a date in one of the Constraints fields based on how you want the task to behave
  4. Save the view as a separate view to refer back to when constraints need to be changed. 

Known Issues

Review also the following articles to see if any of the issues documented apply:

Additional Information

See also: