1. A computer-implemented method for generating electronic data for use in planning the execution of a manufacturing process, the method comprising: receiving defined groupings for multiple execution-level manufacturing operations that are defined in a manufacturing process execution-level electronic data model and that define a process flow to produce a product; determining, for each of the defined groupings, whether the defined grouping includes multiple occurrences of a process step definition that has multiple different defined alternative steps, and if so, changing the defined groupings so that each defined grouping of the defined groupings has no more than a single occurrence of a process step definition that has multiple different defined alternative steps; and generating the electronic data for use in planning execution of the manufacturing process using the changed defined groupings for the multiple execution-level manufacturing operations.