Thanks to everyone who has helped me with this script. *thumbsup*
When I changed the workspace from Design to Run I noticed there was an error in line 17 of the script, (Use of undefined variable 'runLength') .
I added qoutes around runLength and started the flow and now the file went to the HP SmartStream Designer Imposition.
Enfocus Switch 2017, Enfocus PitStop Server 13u2, HP SmartStream 12 & Kodak Prinergy 7.5 with Rules Based Automation
MAN Roland R705 & R708, KBA Rapida 205, HP Indigo 7600, 7800 & 10000, Inca OnsetX2, Durst P10 among other things
.