As ın opalis, Orchestrator has a limit of total number of concurrrent policies that a action server can run. This setting is also known as Action Server Policy Throttle.
If maximum allowed number of policies exceeds, error messages will return or exceptions captured in Policy Module logs.
This setting is configurable by using aspt.exe which found in C:Program Files (x86)Microsoft System Center 2012OrchestratorManagement Server directory.
Syntax is simple;
astp.exe ActionServerName MaxNumber