  We consider the class of single machine scheduling problems with the
objective to minimize the weighted number of late jobs, under the assumption
that completion due-dates are not known precisely at the time when
decision-maker must provide a schedule. It is assumed that only the intervals
to which the due-dates belong are known. The concept of maximum regret is used
to define robust solution. A polynomial time algorithm is given for the case
when weights of jobs are all equal. A mixed-integer linear programming
formulation is provided for the general case, and computational experiments are
reported.
