Issue : Assigned To field is getting auto-cleared on Work Order Tasks

[Sushma Pavani K]

Why is the Assigned To field on Work Order Tasks getting cleared automatically by the system without any manual action?

Could this be due to system-driven logic such as Dynamic Scheduling, auto-assignment rules, Business Rules, Flows, or FSM/WFM configurations that re-evaluate task ownership?

As an added advantage, even though the Assigned To field is cleared, the scheduled details remain visible in the calendar. This allows the team to still view the task and its scheduled time and reassign the task again based on the existing schedule.

[pavani_paluri]

Hi @Sushma Pavani K ,

the Assigned To field on Work Order Tasks in ServiceNow can be cleared automatically by system‑driven logic. It usually happens because of Field Service Management (FSM) scheduling logic or related automation.

Check Dynamic Scheduling
Go to Field Service Management settings.
See if *Dynamic Scheduling* or *Optimization* is turned on.
If yes, the system may be re‑evaluating assignments and clearing *Assigned To*.

Look at Assignment Rules
Navigate to System Policy > Assignment > Assignment Rules.
Check if there are rules for the Work Order Task table (`wm_task`).
See if any rule clears or changes *Assigned To*.

Review Business Rules
Go to System Definition > Business Rules.
Filter for the Work Order Task table.
Look for rules that run on *update* or *insert* and touch the *Assigned To* field.

Check Flows
Open Flow Designer.
Search for flows related to Work Order Tasks.
See if any flow step resets *Assigned To* when the task is rescheduled or updated.

Look at FSM/WFM Configurations
In Field Service or Workforce Management modules, check if there are settings that separate “scheduled technician” from “assigned technician.”
This explains why the calendar still shows the schedule even if *Assigned To* is blank.

Test in a Sandbox by creating and assigning work order task manually and watch what happens when you reschedule or update it — this helps pinpoint which logic is clearing the field.

Mark it helpful if this helps you to understand. Accept solution if this give you the answer you're looking for

Kind Regards,

Pavani P

[Joshua Chen MTL]

@Sushma Pavani K  hey sushma, pls be careful with above answer from pavani, it has many false statements generated from AI

pls provide more details
write down the steps to reproduce and i will be able to help you.
also what version are you in, and if you,ve done any customization to FSM.

also,
unassigned work order task should not be visible in the dispatcher workspace calendar. 
after you refresh, the WOT should be back into the task panels in pending dispatch (it is possible that dynamic scheduling unassign a job if you have configured it so,

if a task remains in the dsw calendar against an agent lane, but assign to is empty - open a defect (assuming you havent done any customization)

[Sushma Pavani K]

Yes, Will it be stopped the unassignment process if the check box is unchecked?

[Joshua Chen MTL]

if this is the root cause, yes... 

without more details i can only lead you toward the obvious path/ first thing to check..

could be custom BR at base task table levels...
could be many things..