The #TSTDC records statistics for a task. Clients may record or query fields in this dsect. If they do, having a detailed understanding of what the fields represent is useful.
The TSTTIMWT is documented as "WAIT TIME (10**-4 SECONDS)" in the #TSTDS Dsect, which represents the Task Statistics table. What wait time does this field actually represent?
The value in the TSTTIMWT field is the accumulated total of all WAITs for the life of the task execution. It is not a a high water mark (HWM) of the longest amount of time the task waited for a single Wait occurrence. The Inactive Interval & External Wait timers measure the longest single interval that a task has waited for a resource. They check for something completely different than what the TSTTIMWT records, so anything that compares these two values will not be useful.
The complete layout of the #TSTDC can be found here: