SELECT *
FROM WRMaster W
WHERE DATEDIFF( minute, W.AckedDateTime, W.ResolvedDateTime )<=
(
 SELECT PriorityKey
FROM FMSLAClassPriorityMap
 WHERE SLAClassKey=(EXEC dbo.GetSLAClass  W.LocationKey,W.ServicCategoryKey,W.ProblemTypeKey,NULL,'')
)