This paper considers the bi-criteria scheduling problem of simultaneously minimising the total completion time and the number of tardy jobs with release dates on a single machine. Since the problem had been classified as NP-Hard, two heuristics (HR9 and HR10) were proposed for solving this problem. Performance evaluations of the proposed heuristics and selected solution methods (HR7 and BB) from the literature were carried out on 1,100 randomly generated problems ranging from 3 to 500 jobs. Experiment results show that HR7 outperformed HR10 when the number of jobs (n) is less than 30, while HR10 outperformed HR7 for n≥ 30. OPSOMMINGIn hierdie artikel word die bi-kriteria-skeduleringsprobleem bestudeer waar die totale voltooiingstyd en die aantal take wat laat is op 'n enkele masjien geminimiseer moet word. Verskeie heuristieke word voorgestel en getoets om sodoende die beste benadering te identifiseer.

No abstract

No abstract

Purpose: This paper focuses on the improvement of the inventory management of repairable parts of the airline company Air Nostrum. The company uses a common sales replacement policy to manage their repairable parts and the same target fill rate for every item. This target is very high in order to assure a high availability of the aircrafts, dealing also to a high inventory value.

Design/methodology/approach: However, this paper shows that an alternative heuristic approach outperforms the previous one terms of inventory value while fulfilling the target fill rate.

Findings and Originality/value: This improvement is illustrated with an extensive and real dataset and may lead to a significant inventory reduction.

Originality/value: Therefore, a company can design its inventory policies applying this heuristic focused on inventory reduction with a service level constraint instead of the usual cost optimization or service level fulfillment.

No abstract