I'm having an issue when creating a workflow rule to notify customers by email of the project progress. I need the criteria to be TASK LIST STATUS not just task status. I don't want our customers getting too many email notifications throughout the project, only when the entire task list for each department is complete. Has anyone found a workaround for this?

I thought about using milestone completion, but that isn't a workflow rule criteria option. I also considered using subtasks, but there isn't a workflow rule to automate completion of the parent task when all subtasks have been completed. I think these are all things that could be beneficial to automate. Any help is much appreciated!

Thanks!