A structure object is locked to prevent changes to the structure object in previous phases of a software life cycle. When a request to change the structure object in a previous phase is received, a change request file is opened. The changed request is approved or denied based at least in part on the previous phase. If the changes request is approved, a document is generated for the change request. Any changes made to the structure object are integrated into the previous phase of the structure object and are also stored in the document. If the change request is denied, the change request file is closed.