Abstract

CUNHA, Maria Elisa; LOPES, José Álvaro Assis  and  POVOA, Ana Paula Barbosa. Locomotives' operability simulation model. Inv. Op. [online]. 2003, vol.23, n.2, pp.113-130. ISSN 0874-5161.

Inventory management is an important area within the organizations since it determines the operability of the organization system. When the material to be managed involves repair, its control is complex and very important. This complexity is due to different reasons like system structure, associated times and multi-indenture item structure. In this paper, a real case study is analyzed which describe the stock management of the CP 1900 Locomotive components. The Locomotives may need repair due to components breakdowns or potential limit reached. Depending on the failure, the locomotives can be repaired at different places that define different echelons in a multi-echelon inventory model for repairable items. Repair time depends on the components' stock on the shelf or, if there are none, on the repair time of the missing items. In the 1900 Locomotives, four items are considered: the diesel engine, the turbo compressor, the traction engine and the system wheels. Locomotives' maintenance can be performed in two different locations depending on the components breakdown ``Região de Manutenção Centro or Sul'' - RMC/RMS or ``Grupo Oficinal do Barreiro'' - GOB. For diesel, traction engines and wheels breakdowns maintenance take place at GOB, second echelon in the system. Locomotives' failures due to turbo compressor malfunctioning occur at RMC and RMS, third echelon. And finally, the components repairs happen at GOB or at GOE, first echelon. A simulation model is developed in this paper to establish the relationship between the average number of operational locomotives and the stock of the four components. A Binomial distribution is used to generate locomotives failures. A limited repair capacity and empirical distributions are assumed for the items repair time.

Keywords : Simulation; Stochastic Models; Decision Aid Systems.

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