Qualitative research often been used when there is a problems or issues that need to be explored. The exploration is needed since certain variables are extracted from informants voices based on their experiences in the phenomenon studied. Interviews is one of the data collection approach in qualitative research. Prior to conduct the interview sessions, qualitative researcher need to prepare an interview protocol to facilitate the process.  Managing software maintenance requires different knowledge and experience from the practitioners. Despite, the emergence of new method in performing software maintenance processes requires deep understanding from the practitioners. Furthermore, introducing agile methodologies in software maintenance imposed significant impact to software industries. This phenomenon sparks the need to understand the practitioners’ thoughts to develop understanding based on their experience. The objective of this study is to refine the previously constructed interview protocol to identify the current practice in agile maintenance and the criteria involved during the selection of agile method. This is to ensure that the protocol is easily understood and covers all research questions and objectives. This study employed the four steps in Interview Protocol Refinement (IPR) framework which is (1) ensure alignment of research questions and interview question, (2) construct inquiry-based conversation, (3) received feedback on interview protocols and (4) interview protocol pilot testing. The IPR framework is a helpful tool in order for researcher to improve the interview protocol reliability and validity. This study presents the design of the interview protocol that was based on the findings from literature review and experts’ validation.