You can view the total number of in progress or pending workflows at any time on the Distributed Execution Status page, and you can use the Workflow History page to determine how long it takes to run a given workflow.
If you have a large number of pending workflows, or if workflows are taking longer than expected to finish, add more Distributed Execution Manager (DEM) Worker instances to pick up the workflows. Each DEM Worker instance can process 30 concurrent workflows. Excess workflows are queued for execution.
You can adjust workflow schedules to minimize the number of workflows that start simultaneously. For example, rather than scheduling all hourly workflows to run at the beginning of the hour, you can stagger their run times so that they do not compete for DEM resources. For more information about workflows, see the vRealize Automation Extensibility documentation.
Some workflows, particularly certain custom workflows, can be CPU intensive. If the CPU load on the DEM Worker machines is high, consider increasing the processing power of the DEM machine or adding more DEM machines to your environment.