A Continuous Review Inventory Model with Advance Policy Change and Obsolescence

In this paper, we consider a continuous review inventory system of a slow moving item for which the demand rate drops to a lower level at a pre-determined time. Inventory system is controlled according to one-for-one replenishment policy with fixed lead time. Adaptation to the lower demand rate is achieved by changing the control policy in advance and letting the demand take away the excess stocks. We showed that the timing of the control policy change primarily determines the tradeoff between backordering penalties and obsolescence costs. We propose an approximate solution for the optimal time to shift to the new control policy minimizing the expected total cost during the transient period. We found that the advance policy change results in significant cost savings and our model yields near optimal expected total costs.inventory control;obsolescence;spare parts;excess stock;installed base;advance policy changes

An Inventory Model for Slow Moving Items Subject to Obsolescence

In this paper, we consider a continuous review inventory system of a slow moving item for which the demand rate drops to a lower level at a pre-determined time. Inventory system is controlled according to one-for-one replenishment policy with fixed lead time. Adaptation to the lower demand rate is achieved by changing the control policy in advance and letting the demand take away the excess stocks. We show that the timing of the control policy change primarily determines the tradeoff between backordering penalties and obsolescence costs. We propose an approximate solution for the optimal time to shift to the new control policy minimizing the expected total cost during the transient period. We find that the advance policy change results in significant cost savings and the approximation yields near optimal expected total costs.inventory control;obsolescence;spare parts;advance policy change;excess stock;installed base

Morfologia de frutos, sementes, plântulas e plantas jovens de Guibourtia hymenifolia (Moric.) J. Leonard (Fabaceae)

Guibourtia hymenifolia (Moric.) J. Leonard (Fabaceae) é uma espécie arbórea de potencial madeireiro com ocorrência natural nas florestas estacionais deciduais e semideciduais sob afloramentos calcários na Serra da Bodoquena, Mato Grosso do Sul, Brasil. Foram descritos e ilustrados os aspectos morfológicos dos frutos, sementes e desenvolvimento das plântulas e plantas jovens de G. hymenifolia. O fruto é do tipo legume, deiscente, unispermo. A semente possui forma elíptica, forte coloração alaranjada e presença de arilo esbranquiçado de origem funicular. Obtiveram-se 66% de germinação em câmara de germinação, sendo a morfologia inicial das plântulas fanerocotiledonar epígea, com cotilédones carnosos. As plântulas e plantas jovens apresentam mudança de filotaxia, sendo os eofilos opostos e unifoliolados e os metafilos, alternos, peciolados e bifoliolados. Eofilos e metafilos apresentam nervação pinada do tipo camptódromo broquidódromo. Esses resultados contribuem em estudos taxonômicos da espécie e permitem a identificação das plântulas em estudos de regeneração natural