How to make an automatic task run by a user? it is a system task, but we want it

Hi shaoyong,
As far as I know,If the node have an option to make it quicktask then you can change the assignment properties by going to the assignment tab of that node and choose "This node will be assigned as a task to a person or a group of people"
otherwise we won't able to change the assignment properties except to choose process initiator/Owner.

In my case, I have a "Lock Document" system task. How can I specify the Lock By user if user other than process initiator can submit the form and lock the document?

You might have luck putting the Lock Document task in a sub process, set the sub process as assigned to the user you would like to lock under, then set the Lock Document task to run as the process initiator in the sub process.

csteward, I have tried your way but turns out not good. This will create a task instead of excuting automatically.

Ah yes, that will not work for your case. I'm not sure if this will be possible unless you can log in as that specific user and publish the sub process under their account - in this case, you could set the sub process to run as "whoever designed this process model". This won't work if your user needs to be dynamic however.

Hey, you can just use sail form with yes button and put an xor gateway in front of it so if user clicks yes or ok button the flow goes to your automatic task else to either end or anything elae according to your requirments