This research addresses on developing heuristic model with discretized time horizon for solving the
alternative machine scheduling problem on single operation. The objective function is to minimize total
weighted tardiness. To develop the model, there are some asumptions : (1)All the jobs are considered
available at the time k=1, (2)Processing time job already includes the set up time, (3) The execution of a job
nonpreemptive, (4)K time horizon considered long enough to complete all the jobs, Ci  K for all I, (5)Every
job is done simultaneously between one machine and one operator. The Model is applied on numerical
instance 10 jobs 6 machines and having a good solution.
Keywords: scheduling, alternative machine, heuristic, discrete time horizon