creo3 config.pro option documentation for: PIPING_DESIGN_METHOD 
piping_design_method
(Non Spec-Driven)
non_spec_driven
, spec_driven
, user_driven
*
Specify the piping design method for the piping project.
non_spec_driven
- Activates the Non Specification-Driven piping design mode.
spec_driven
- Activates the Specification-Driven piping design mode.
user_driven
- Activates the User-Driven piping design mode. This mode allows you to switch between Specification-Driven and Non Specification-Driven piping design modes and convert existing assemblies at any time in the design process.