Operations research is a methodology for analyzing problems and developing solutions in healthcare delivery. It involves 3 phases: 1) problem analysis which defines the problem, analyzes subsystems, and establishes priorities, 2) solution development which specifies objectives, decision variables, constraints, and develops analytical models, and 3) solution validation which designs and implements field tests to evaluate and integrate solutions. An example of applying this process is analyzing high default rates in a TB control program to identify factors influencing compliance and develop interventions to address them.