Results are presented of a test, made on a 3.17-ha wheat farm in Pakistan, of a mathematical model for evaluating irrigation system improvement alternatives. In developing the model, water conveyance, application, and water use subsystem models were calibrated with data from the test site. Efficiencies of the existing irrigation system were 39% for application and 53% for conveyance. Optimal design of the application system with precision land leveling provided net benefits of PKR 3625, compared to PKR 2612 under traditional field conditions. Canal lining was not economical. Earthen improvement of the conveyance system yielded a net profit of PKR 3304. Improvement of both the application and conveyance systems almost doubled the total net benefits (although with an increased level of investment), largely due to an increase in irrigated area. The benefit-cost ratio of each improvement alternative was different. The difference in benefits between improving the conveyance system and improving the application system was small, but there was a significant difference in net benefits between any single improvement and the combined improvement of the application and conveyance systems. Ten tables are included. (Author abstract, modified).