How do I create an "If / Else" statement in SPD2013 for 3 task outcomes in a SP workflow?
Just create 3 If branches in a step, each one checking if the status equals one of the statuses in your outcome. Then in each of those, perform the necessary logic to handle each of your scenarios. You don't have to have else branches in them. If it doesn't match the first if, it will continue to the second if. If it doesn't match the second if, it will go to the third.
I think you will have to either manage another column and check it if approved, then which branch it should go. Then another way is using the percentage of completion. When completing the task if it is 0% completed, then Outcome 1. If 50% then outcome 2, If 100% then outcome 3.
Then take the value of the particular column (custom/ percentage) and then assign it to a new variable by querying through task id and then put the if-else to check which branch it should proceed.