“…The scarcity of data has resulted in great difficulties in modeling the natural physical deterioration, let alone the measurement and modeling of maintenance effectiveness, which many people would think requires data immediately before and after the maintenance activities. Therefore, although there have been degradation models for water and sewer pipes in the literature (e.g., Baik, Jeong, & Abraham, 2006;Duchesne, Beardsell, Villeneuve, Toumbou, & Bouchard, 2013;Kleiner, 2001;Lin & Yuan, 2019;Tran, Perera, & Ng, 2009;Wirahadikusumah, Abraham, & Iseley, 2001), researchers have been busy dealing with the issues arising from lack of data and left the maintenance effectiveness untouched.…”