How to auto closure ticket after 3 days.

How to auto closure ticket after 3 days.

Hi, I would like to ask regarding this closure after 3 days.  I already follow step  "Go to Setup->Supervise->Create Rule->Enter a name->Next->Criteria->Hours since requester responded is 72 -> Actions ->Field Updates ->Status - closed." That published by Prashanth but seems like the tickets not being closed after 3 days. Are there any steps that I missed?