Workflow was not works on child object when criteria was used parent object

Question

I have two objects , one is parent(Account) and second one is child(Temp) and both of have master details relationship.

I have created one workflow on Temp object and used rule criteria of account object. and below is the criteria.

Account number equals 10

and checked the radio button "Evaluate the rule when a record is created, and any time it's edited to subsequently meet criteria"

whenever the workflow fires "task" will generate.

to run the workflow i have made the changes in the account number form 10 to 11 and then again 10 but workflow was not fire any of the case.

Could you please suggest if i am miss something here so due to limitation it was not working

Thanks in advance.....

Answer 1

As @Eric says, changes to a parent object won't trigger DML on the child object (and hence WF on child object won't be triggered)

Using a cross-object formula field on Child that pulls in the parent's Account Number also won't work as formulas are evaluated at record retrieval time and aren't actually saved in the object - thus, no DML event.

Hence, you have two options

Option 1 - Process Builder

Process Builder can push a change in a parent object into every child object. This will definitely cause a DML update on the child and hence workflows will fire on the child

Option 2 - Trigger An after update trigger on parent can push the changes in the parent into some or all of the child objects. Those child objects touched will also cause Workflow to ensure

Answer 2

Workflow rules on child objects do not fire when the parent is updated.

In order for the workflow rule on the child to be executed the object where the WFR is defined on will need to be edited / touched

Evaluate the rule when a record is created, and any time it's edited to subsequently meet criteria

Record and it refer to the object the WFR is attached, in your case the "Temp" object