It's possible to map the IT Automation to run when a memory % or cpu % reaches a particular threshold. This can be configured for service or application when the threshold is met.
However, it's not possible to set the threshold for absolute values like 1GB RAM now and we will take giving "absolute value" as a feature request.
The configuration for this can be done at two levels,
1. Attribute Level - Configuration Profiles > Threshold and Availability
2. Process or Service Level - Edit Service/Process Page
The first option will execute the IT Automation when the overall CPU utilization exceeds the set threshold, while the latter will execute the IT Automation when the particular service/process' CPU utilization exceeds the set threshold.
Please refer our documentation for more details,
Hope this helps. Let us know for any other queries.