It is even simpler than that. You don’t need a service, just use a branch statement with evaluate labels set to true.
If your pipeline variable is say: myDoc1/accountBalance
Then add a branch statement with Evaluate Labels set to true
Then add a sequence and put the following in the label
%myDoc1/accountBalance% < 1
put your zero/negative logic there
then put another sequence with $default for the label
and put your positive logic there.
Hope this helps,
Roger
#Flow-and-Java-services#webMethods#Integration-Server-and-ESB