Symptoms

Issue: _1.Workflow is triggered after an item is created with "Assigned to" field and a product field is filled out by the originator.

Question: How do I pause workflow until a particular field is filled out ?

2) Once the task is completed, the workflow should update the list item's "status" field to "completed" and send an email to the originator.

Question: When a user changes the status to "In Progress" and revisits the link to continue filling out the form to complete it, the Edit form link is no longer accessible to the user. What is the best way to automate this process of changing the status? It should give the user to set status to "Not Started", "In Progress" and "Completed"
 

Diagnoses

After review and testing
 

Resolution

Issue _1: The only thing I can suggest regarding this requirement is to use Get List Item by ID SmartObject to retrieve the value of Product column and verify if it’s empty or not. If it’s empty, then route the process to a user task to let user update the Product column of the list item.

Issue _2: The reason that after user selects In Progress or Not complete action, the Edit form link is no longer accessible to the user when they revisit the link to continue filling out the form to complete it is that the workflow does not have the outcome setting to route the process back to the Assign activity.
I would suggest you try adding the outcome for both “Set Status to Not complete” and “Set Status to In Progress” to route your process back to Assign activity.