Ooi, CE & Ooi, LH 2015, 'Instrumentation and monitoring management for a mass rapid transit project in Kuala Lumpur, Malaysia', in PM Dight (ed.), FMGM 2015: Proceedings of the Ninth Symposium on Field Measurements in Geomechanics, Australian Centre for Geomechanics, Perth, pp. 275-288, https://doi.org/10.36487/ACG_rep/1508_16_Chow_Ern (https://papers.acg.uwa.edu.au/p/1508_16_Chow_Ern/) Abstract: The underground section of the Kuala Lumpur Mass Rapid Transit (MRT) project consists of 9.5 km of tunnelling works, seven underground stations, two portals and six shafts. In order to ensure public safety and to verify the performance of the retention system and tunnelling works, a vast number of instruments were installed on surface and sub-surface. The monitoring data acquired during excavation and tunnelling was benchmarked against the predictions made for this project. It is crucial that appropriate actions are taken when there is a breach in the preset levels. In view of the enormous volume of instrumentation data to be monitored, several specialist subcontractors were appointed to undertake the task. In order to get the information to various parties such as the operation team, designer, client, and authorities, an effective system is required to manage the data generated from the project. A web-based data management system (DMS) was adopted to handle the large amount of instrumentation data and to streamline the monitoring process by standardising data from different subcontractors to be imported by DMS. This paper present the methodology adopted and some of the subtle challenges faced in this project.