1. A method, performed by a computer system, of performing a merge operation where changes included in a second version of a first exported Business Process Execution Language (BPEL) implementation and an information technology (IT)-side modified version of the first exported BPEL implementation are propagated to a merged BPEL implementation, wherein the first exported BPEL implementation includes activities in a first business process flow modeled by a first Business Process Modeling Notation (BPMN) model, the second version of the first exported BPEL implementation includes changes made by a business unit to the activities included in the first exported BPEL implementation, the IT-side modified version of the first exported BPEL implementation has changed IT scopes and/or activities added by an IT unit subsequent to generation of the first exported BPEL implementation and a scope is a logical collection of activities, the method comprising: when the merge operation is a forward merge operation: copying, by the computer system, an outline of the second version of the first exported BPEL implementation to the merged BPEL implementation; adding, by the computer system, modified IT scopes from the IT-side modified version of the first exported BPEL implementation to the merged BPEL implementation to perform an outline merge, where modified IT scopes from the IT-side modified version of the first exported BPEL implementation are added to the merged BPEL implementation either by anchoring added IT scopes to a previous activity in the merged BPEL implementation or by anchoring added IT scopes to a subsequent activity in the merged BPEL implementation if a previous activity is not available; matching, by the computer system, activities in the second version of the first exported BPEL implementation and the IT-side modified version of the first exported BPEL implementation by comparing previously created hash map identifiers for each activity timestamps; creating, by the computer system, a timestamp capturing a last update time of an activity in the second version of the first exported BPEL model; creating, by the computer system, a timestamp capturing a last update time of an activity in the IT-side modified version of the first exported BPEL model; comparing, by the computer system, timestamps to determine if an activity in the second version of the first exported BPEL implementation has been changed more recently than a matched activity in the IT-side modified version of the first exported BPEL implementation; copying details of a matched activity of the IT-side modified version of the first exported BPEL implementation to the merged BPEL implementation only when the matched activity in the IT-side modified version of the first exported BPEL implementation has been changed more recently than a matched activity in the second version of the first exported BPEL implementation to establish precedence of business unit changes over IT unit changes; and performing, by the computer system, an attribute level merge for updated branch conditions in the merged BPEL implementation by replacing conditions for a switch in the merged BPEL implementation with conditions from the same switch in the IT-side modified version of the first exported BPEL implementation if the conditions are different; and when the merge operation is a reverse merge operation: converting the IT-side modified version of the first exported BPEL implementation to a modified BPMN model; and adding scopes and branches from the modified BPMN model to a merged BPMN model including changes made by the business unit to the first BPMN model.