Long running Groovy script

We have a rather long running Groovy script which makes a number of web calls based on various bits of logic. We've set up a test case which runs this using the "Script Runner" component and the "Fixed Rate" component to trigger it. What appears to be our problem is that if the script is triggered before the previous run has finished it's marked as "Failed" (presumably because it never reached the end of the script) i.e. if we set the Fixed Rate component to trigger the script every 5 seconds and the Groovy script takes 20 seconds to execute all runs will be marked as "Failed".

Is there a way for the Groovy script to delay execution of future runs until it's completed? Or is there another way to achieve this?

Apologies if this is obvious but I'm new to both Groovy and LoadUI.

Thanks in advance.
Kevin.