Changes to a reusable transformation that you enter through the Transformation Developer are immediately reflected in all instances of that transformation. While this feature is a powerful way to save work and enforce standards, you risk invalidating mappings when you modify a reusable transformation.
To see what mappings, mapplets, or shortcuts may be affected by changes you make to a transformation, select the transformation in the workspace or Navigator, right-click, and select View Dependencies.
If you make any of the following changes to the reusable transformation, mappings that use instances of it may be invalidated:
When you delete a port or multiple ports in a transformation, you disconnect the instance from part or all of the data flow through the mapping.
When you change a port datatype, you make it impossible to map data from that port to another port using an incompatible datatype.
When you change a port name, expressions that refer to the port are no longer valid.
When you enter an invalid expression in the reusable transformation, mappings that use the transformation are no longer valid. The Integration Service cannot run sessions based on invalid mappings.