When placing a fitting on a pipeline, the prescribed method of fitting placement is more than suitable to locate and configure a fitting on its respective pipe line.
When redefining a fitting, it gives you the option to redefine a point and change the orientation, which only allows you to "flip" the fitting along the pipe axis around a center point and or rotate the fitting around the aforementioned pipe axis but not adjust the distance from the plane (or change the reference) that was the initial datum for originally locating that fitting.
For instance, if you have placed a "Tee" fitting in a particular location using a surface as a reference, and due to a design change, the designer is required to place a check valve before the "Tee" fitting, currently in Creo 4.0 you would have to delete the "Tee Fitting" and replace it at the required distance.
This creates major problems due to the fact that prior to the design change of requiring a check valve (gauge, reducer or any component) , a designer may have created a new pipe branch off of the "Tee" fitting with a myriad of components and lengths. A large portion of the design will have to be deleted ( and then recreated) regardless of how convoluted the design was. Merely to replace one "Tee" at a different distance from a reference plane.
If replacing only one component, it amounts to a few extra clicks, when having to replace 20 fittings/components and piping, as any engineer knows, it adds up and causes frustration.
Hence the suggestion: When adjusting a fitting that has been placed on a pipeline, a prompt for the reference plane, with the current distance from that plane needs to show and that value needs to be adjustable (within the boundaries of that pipe)....If a designer requires to increase the length of a pipe, the Z location from the reference plane needs to be adjustable as design intent has changed and more than likely, the location of the fitting needs to change which currently, cannot occur easily. Thank you.