Equipment maintenance system has been given great consideration to any industry to make any equipment available. To avail equipment in productive operation, among the techniques from which are known is that total quality management (TQM) implementation system. Most of the time; equipment or machineries are seen down due to part failure, process failure, improper handling etc. In the case company there are also similar problems that have been detected such as maintenance quality problem, spare part supplying delay, equipment down time, and maintenance reworks. Due to these, the maintenance department faces challenges of quality maintenance and customer satisfaction. In fact, the corporation is actually performing total quality management activities in which it is not in continuous approach. In Ethiopian construction Works Corporation (ECWC) maintenance department is implementing top-down approach in which the TQM linkage with maintenance is weak. Therefore, this study purpose is to improve these problems hindering the operational productivity of equipment maintenance system using the total quality management technique. The objective is met through a research method of qualitative and quantitative data collection and analysis. The data sources were from primary and secondary data. The primary data obtained are from interview, questionnaires, field visit, process mapping and simulation. The secondary data were obtained from ECWC reports, literature review and other data bases. The approaches used was TQM process mapping tool method and arena simulation software to validate the improved process mapping to seek an improvement of equipment maintenance productivity. The study finding indicated that there are long maintenance time, high failure rate, weak process management system, and weak interdepartmental linkage. This study also found that shifting from practice of quality control towards preventive actions into work reduction of Spare part supplying delay, down time, maintenance reworks and increase the level of the commitment of management/leaders. The data are also analyzed using different software mentioned here and model developed by triangulating Business Process Mapping (BPM) and Quality Business mapping Process (QBMP). Operational productivity of equipment maintenance with total quality management (TQM) helped to improve 80% of process path of operational productivity of equipment maintenance system. It has also helped to increase the feeling of empowerment among employees and to involve the people closest to the process mapped and the quality efforts in other departments of the ECWC. This research implication is to improve the maintenance system of the ECWC which also implies to improve any similar industries maintenance system. The research has a contribution to the body of knowledge from perspective of integrating the maintenance system to TQM which is effective in reducing the maintenance operational time. In general, this research has identified problems and reduced those problems integrating TQM into maintenance system.