Excellent maintainability is extremely important not only supplementing reliability necessarily but reducing product life cycle cost and enhancing its quality greatly. Industrial experiences have shown that wear and friction related failures of tribological components, are one of the main reasons for maintenance. However, most of the research works evaluated tribo-maintainability at maintenance stages. This paper analyzed the tribo-maintainability related design factors from systematic perspective and concluded a more complete set of six factors. A fuzzy set based approach is then developed to quantitatively evaluate design for its tribo-maintainability. A case study with a common assembly of a gear reducer has demonstrated the effectiveness of the prototype developed.