For the request being processed, determine the correct path for
the data from input to output.
Determine each program and component involved.
Check for messages about problems in these programs and components.
If an installation-provided exit routine receives control during
the processing, check the routine.
Look at the environment. Specifically, look for recent hardware
and software changes to the system and to any applications. A change
in one program can affect others; for example, a change to an application
that updates a database affects all other users of the database.
If needed, recreate the problem, using a SLIP trap and traces
to obtain the data needed to isolate the problem.