Tabu search for the single machine sequencing problem with ready times

We consider the minimisation of the mean completion time and the makespan in the single machine scheduling problem with ready times. A tabu-search-based heuristic procedure is proposed to find the sequence which allows one to reach a value of the cost function as close as possible to the global minimum. Computational tests have been carried out to compare the performances of the tabu search procedure with those of a branch and bound algorithm which gives the optimal solution for problems that are not too large. A comparison has also been made with three heuristics, recently presented by Liu-MacCarthy, which have given good outcomes both in terms of mean completion time and response time. Our comparisons have been made both in terms of mean completion time and makespan. The tabu search response time has been considered to asses the reliability of the method. Computational tests show that, with respect to the completion time, the tabu search yields excellent sequences