Research shows that approximately 40% to 60% of the maintenance effort, devoted to understand the modified software. One of the obstacles founded in software maintenance is the lack of contained knowledge in software. This research proposes a conceptual framework in software maintenance by utilizing knowledge management process and software comprehension using ontology as formal modeling analysis to expliciting the tacit knowledge in software. The topic of software comprehension is an important part for software engineer's effort. This framework is realized by means the Requirements Recovery and Reconstruction (R3) method based Software Tools (R3ST) environment. R3ST bind to domain ontology for increasing the contextual result. It is expected that R3ST would be able to facilitate software developers in software maintenance activities.