When you already created learning outcomes, it will sort by last updated. However, you can reorder learning outcomes as needed, but it must be an additional learning (You can not reordere the learning outcomes from the course.). Follow these steps:

[[1.]] Go to menu Plan m
[[2.]] Click Define Learning Outcomes tab
[[3.]] Click Reorder next to additional learning outcomes

[[4.]] The system will show Reorder Learning Outcomes window. Place the mouse at arrow in before wanted learning outcome, then Hold and Move up and down to reorder it. 
[[5.]] Click the Save button.