1. A method performed by a processor based on instructions of a memory accessed by the processor, the method comprises creating a consolidated process model from at least two sub-models stored in the memory while resolving conflicts and dependencies between the at least two sub-models, the method comprising: specifying, by the processor, a plurality of change operations of the at least two sub-models, the at least two sub-models including control nodes having a decision node, a merge node, a fork node, a join node, an initial node and a final node, the at least two sub-models including extension fragments enabling a representation of a decomposition of the at least two sub-models, the extension fragments including at least one of an alternative fragment having the decision node and the merge node, a concurrent fragment having the fork node and the join node, and a complex fragment including a combination of the control nodes; determining, by the processor, a plurality of critical pairs between the specified plurality of change operations; deriving, by the processor, a dependency matrix for the specified plurality of change operations by specifying the dependencies for each critical pair in terms of operation parameters, the dependencies being captured by the dependency matrix, wherein a joint process structure tree is utilized to optimize the dependencies; deriving, by the processor, a conflict matrix for the specified plurality of change operations by specifying the conflicts for each critical pair in terms of the operation parameters, the conflicts being captured by the conflict matrix; determining as the conflicts, by the processor, conflicting change sequences from the specified plurality of change operations, wherein if any conflicting change sequences are determined then the conflicting change sequences are presented for resolution; resolving, by the processor, each of the conflicting change sequences when presented for resolution to produce a corresponding resolved conflict of a plurality of resolved conflicts by selecting which operations of the specified plurality of change operations to commit in accordance with user input that identifies one of a plurality of conflict resolutions; determining, by the processor, independent subsequences from the specified plurality of change operations based on the dependency matrix; determining, by the processor, conflicting subsequences from the specified plurality of change operations based on the conflict matrix; and merging, by the processor, the independent subsequences and the conflicting subsequences to create the consolidated process model, wherein determining, as the conflicts, the conflicting change sequences from the specified plurality of change operations comprises: iterating, by the processor, over all subsequence pairs for the change sequences such that, for each of the subsequence pairs performing a pair-wise comparison of any two change operations of the specified plurality of change operations and identifying whether or not the any two change operations of the specified plurality of change operations are in conflict, and if in conflict, then presenting, by the processor, the conflicting change sequences for resolution, wherein the resolving of each of the conflicting change sequences includes: unifying conflicting change sequences, applying an insert fragment operation on the consolidated process model, presenting two new conflicts for selection, identifying which change sequence to select based on the user input, and producing the change sequence as a resolved conflict, wherein the joint process structure tree is constructed by constructing individual process structure trees and combining the control nodes based on a given matching of elements used to derive a matching of the extension fragments to reduce a number of the pair-wise comparison for a given one of the plurality of change operations.