Tilahun Derib (PhD)Eden Halefom2024-06-262024-06-262021-07-01https://etd.aau.edu.et/handle/123456789/3216In developing countries like Ethiopia, satisfying the access of water supply, sanitation and hygiene to the community is a huge challenge. These challenges are opposed in different sectors by various methods. Among the efforts of United Nations Organization to fulfill this goal includes, setting international plans such as Millennium Development Goal, Supporting countries in financial, human resource, training and infrastructure. Even with all these efforts, access to water supply and sanitation ratio in sub-Saharan Africa is still at its lower rate. Access to water supply and sanitation in Ethiopia is amongst the lowest in Sub-Saharan Africa and the entire world. The major challenge for water supply and hygiene in Ethiopia is to maintain a year-round and adequate supply to meet people‘s need. The purpose of this research is therefore, to develop rule-based expert system for WASH projects delay management in the case of WASH water supply construction projects in Ethiopia. To achieve the expectations of this system, the methodologies followed in this system were knowledge acquisition using structural interview and workshop as one of primary knowledge source. The required data was gathered from sources such as; first identified the list of causes and effect from the different documents and also through workshop with the group of construction management masters students of Addis Ababa university and also finds the delay causes and effects of 15 towns water supply and sanitation project from their technical audit report arranging in the rule-based form or ―if…then‖ form and in the next phase structured interview was employed with selected experts and come with list of probable solutions and causes of delay. Finally rules for delay management was formulated by the rule-based expert system. Domain experts were selected by using purposive sampling techniques from the experienced experts from construction sector and academicians. After the development of knowledge-based system, verification and validation tests were employed. The study certainly answered the problem of the water sector delay problems because it can identify the cause and solution of the delay regarding the experts view and experiences. As a recommendation additional studies are needed for the rule-based expert system to develop in different soft wares. Key words: Delay management, Expert, Rule based expert system, WASH project , WaterenThesis