Abstract: This study discussed the relationship between design for assembly and maintainability in order to remain product/system performance and at the same time to extend their life. The maintenance efficiency is measure based on maintainability index, which is derived based on several assembly criteria such as disassembly, assembly direction and tools used. To increase the maintainability, redesign of the potential components based on design for assembly guideline have been made. A case study of drum brake is carried out to clarify the work.