The Klimov model concerns the optimal dynamic scheduling of a multiclass M/G/1 queue with general Bernoulli feedback of jobs and linear holding costs. In his seminal 1974 paper, Klimov established the optimality of a static priority‐index rule for such a model under the average cost criterion and gave an adaptive‐greedy index algorithm, via a novel linear programming approach. The model has rich and insightful connections with stochastic scheduling and bandit problems, and has found use in a wide variety of applications, most notably in time‐sharing computer‐communication and flexible manufacturing systems.