How IDMS treats task level statistics is controlled by the STATISTICS clause of the System Generation SYSTEM statement.
If NOTASK is specified, task level statistics are not maintained at all.
To maintain task level statistics (i.e., the #STRDS control blocks are connected to the TCE), TASK must be specified, and COLLECT or WRITE should also be coded.
COLLECT means that task level statistics are collected but not written to the dc-log.
WRITE means that task level statistics are collected and also written to the dc-log.
Most SREPORTS require that WRITE be set (see also SREPORTS available with COLLECT).
Performance Monitor maintains its own statistics but it requires that TASK COLLECT or TASK WRITE be specified in the SYSTEM statement.
The AMDCLOG and IMDCLOG parameters in #PMOPT can be used to indicate whether or not Performance Monitor statistics are written to the dc-log.
If Performance Monitor statistics are not written to the log, then the batch reports can not be run from the log.
In this case, it would be necessary to use SMF - see the AMSMF and IMSMF parameters in #PMOPT and Using SMF to Archive Statistics.