Hi Brian,

• If by Service you mean a Calm object Service within a blueprint, there is no option for disable it today. The way to address this would be with a higher layer, a Calm Runbook. You would have independent blueprints per service, and via a Runbook you would let the user select what Services to include. Then your runbook will request each of those blueprints. Be aware this will create independent applications in Calm with segregated lifecycle management.
• If by Service you mean to install or not some software within a Calm object Service, then you can make on your task code an IF statement that checks what the user has selected during launch.

Hope this helps.