To reduce the number of runtime adjustments, increase the number of worker processes that are available to parallel queries. You can do this either by adding more total worker processes to the system or by restricting or eliminating parallel execution for noncritical queries, using either:
set parallel_degree to set session-level limits on the degree of parallelism, or
The query-level parallel 1 and parallel N clauses to limit the worker process usage of individual statements.
To reduce the number of runtime adjustments for system procedures, recompile the procedures after changing the degree of parallelism at the server or session level. See sp_recompile in Adaptive Server Reference Manual: Procedures.