Replacement of Automotive Assets at Nakhon Ratchasima Rajabhat Universit

Abstract

Most vehicles at Nakhon Ratchasima Rajabhat University have been in service for extended periods, resulting in high operating costs, increased safety risks, and rising emissions. This study aimed to: (1) analyze vehicle performance and efficiency; (2) examine cost-effectiveness using engineering economics; and (3) propose appropriate replacement alternatives for automotive assets. The sample consisted of 20 vehicles with service lives ranging from 7 to 27 years. Data were collected over 12 months and analyzed using process capability indices (Cp, Cpk), carbon footprint assessment, life cycle cost (LCC), net present value (NPV), payback period, and break-even analysis. Results revealed that five vehicles aged over 20 years exceeded fuel consumption standards by up to 74.80%, recorded Cp and Cpk values below the standard threshold, emitted a total of 110,105.63 kgCO₂eq per year, and recorded an NPV as low as 1,012,108 baht, indicating that continued operation is no longer economically justified. For replacement alternatives, passenger cars with high utilization should be replaced with EVs or hybrids, reducing operating costs by 82.15% and 60.79%, respectively. Vans should adopt a two-track approach, transitioning initially to B20 or hybrid alternatives before scaling toward full EV adoption, which reduces costs by 74.53%. Large buses should switch to B20 biodiesel, achieving cost reductions of 53–67% and cutting CO₂ emissions by 15%. Vehicles with very low utilization should shift to a car sharing system rather than continued ownership.