This case study presents the design of a chiller plant for high-rise buildings using a risk analysis with Monte Carlo simulation and Six Sigma process capability. The study used defects per million opportunities (DPMO) to identify potential risks associated with the chiller plant. The results of the study showed that Six Sigma had a high level of process capability and was able to meet the design requirements of the chiller plant for high-rise buildings. Process capability analysis is a key component of Six Sigma, which helps organizations to assess their ability to consistently produce products or services that meet customer requirements. Several potential failure scenarios might be identified for the chiller plant including inadequate cooling due to equipment failures, and design errors of pumps, cooling tower, and air handling unit (AHU) fans, which could have an adverse impact on the process capability. By conducting a risk analysis, organizations can identify potential failure modes, evaluate their impact on the process, and develop strategies to mitigate such risks. The study recommends implementing controls to mitigate these risks and improve the overall performance of the chiller plant design for high-rise buildings.