A nonproprietary simulation template named POST (Plant Operations Simulation Template) has been developed for use with a spreadsheet program. The template provides for mathematical simulation of central heating/cooling plant equipment including cooling towers and centrifugal chillers. It provides methods for configuring a simulation of a specific physical plant, defining operating conditions and time-dependent boundary conditions, running simulations, and graphing simulation results. POST is a flexible and highly portable analytical tool for plant equipment operators and engineers concerned with efficient operation of physical plant systems.Units: Dual