Software merge: Combining changes to decompositions

Computer aid for software evolution is needed for more effective software development, particularly in contexts where changes to large systems must be made rapidly. This paper addresses computer aid for the evolution of requirements models and high level software designs. We present an improved method for automatically merging changes to software designs expressed via annotated dataflow diagrams and hierarchical decomposition. This improvement addresses the structure of the design as well as the system behavior the design implies. We also present an improved method for automatically reporting and repairing conflicts between structural changes. These methods can be applied to the informal dataflow diagrams commonly used in requirements modeling and software design as well as to the more specific executable design representations used in the computer-aided prototyping system CAPS.