Abstract:
Yapi Merkezi deals with the design and construction of a wide variety of buildings, rail systems and heavy construction projects. In Tanzania, Yapi Merkezi has given a contract for first two phases of standard gauge railway construction project with five phases from Dar es Salaam to Mwana that cover approximately 1800 Km. For the aim of project fulfilment, rocks should be removes to provide material for concrete aggregates. About 70% of concrete aggregates are obtained from hard rock quarries by drilling and blasting. For that case availability of drill rigs seem to have problems of frequent breakdowns which affect concrete aggregates production performance.
Therefore, this study aimed at developing maintenance management system to improve availability of those quarry drill rigs. In achieving the main objective of the study, structured questionnaires, observation method and documentary review used as means of data collection. The collected data were analysed by using Statistical Package for Social Sciences (SPSS) version 26 in which regression analysis was applied. Also, Microsoft Excel and Relative Index (RII) were used to rank the identified variables, which affects the current management of the quarry drill rigs.
Findings from the study reveal that the availability of quarry drill rigs for the current maintenance practices is 46.38% which is very low and hence justified a need for developing Maintenance Management System. The study identified and analysed availability variables as Rotation unit effectiveness (0.041), Effective compressed air pressure (0.030), Total wear out of parts (0.305), Effective engine RPM (0.260), Defective sensors (0.054) and Effective hydraulic pressure (0.048). Based on the identified factors, the researcher developed and validated a maintenance management model with predictability accuracy of 95.98% confidence level.
Furthermore, the researcher developed CMMS which improved drill rig availability from 46.38% to 95.1%. This concludes that the developed system is more efficient and hence can contribute significantly to drill rig availability improvement and therefore fulfills the production targets. It is recommended that, Yapi Merkezi should control and monitor its maintenance management practices at a specified time interval (daily, weekly and monthly), to make sure that maintenance management system works perfectly and complying with the maintenance management standards.