The Question is:
Where can I get information (documentation), about DEC Scheduler product?
The Answer is :
From Computer Associates (CA), the current owners of the package
formerly known as DECscheduler. The DECscheduler package was sold
to CA some years ago.
Other scheduling packages are available for OpenVMS, please see
the CSA software catalog mentioned in the OpenVMS FAQ. Also see
the Kronos Freeware package on Freeware V4.0 -- other Freeware
scheduling packages, including the Queue Utilities package, may
well be of interest.