The Web Services Hub determines when to start another instance of a web service workflow based on the current resource usage and the following properties of the web service workflow:
Service time threshold.
If the average time that it takes the Web Services Hub to process a web service exceeds the service time threshold, the Web Services Hub starts another instance of the web service.
Maximum run count per hub.
The Web Services Hub starts an instance of the web service until the number of instances reach the maximum run count for the hub. If the maximum run count is reached, the Web Services Hub does not start a new instance of the web service even if the average service time threshold.