The investigation of life cycle cost on the basis of functional diagnosis in Tha Ngon project in Laos

In recent years, the deterioration of irrigation facilities has been progressing in the countries of Southeast Asia, as well as Japan. Hence, it is vital to introduce the concept of stock management, which decreases their life cycle costs. Life cycle costs of each scenario that combined construction methods and timing of implementation were compared by using single curves degradation prediction model and the Markov chain model as method of degradation prediction based on the result of the functional diagnosis executed in Laos Tha Ngon project area. Scenarios were made from combined types of frequency of operation and maintenance (O&M) of facilities, which were low-frequency, medium-frequency and high-frequency, with types of quality of construction method, which were low-quality, medium-quality and high-quality. As a result, in case of Laos Tha Ngon, a scenario combined middle-frequency of O&M with middle-quality of construction method has become the lowest cost in the four scenarios. This process was shown as a method in stock management which attempts to maintain long life for irrigation facilities and contributes to efficient budget implementation through the reduction of the rehabilitation and the renewal of projects expense.