Sustainable sourcing of strategic raw materials by integrating recycled materials

In this paper we investigate a manufacturer's sustainable sourcing strategy that includes recycled materials. To produce a short life-cycle electronic good, strategic raw materials can be bought from virgin material suppliers in advance of the season and via emergency shipments, as well as from a recycler. Hence, we take into account virgin and recycled materials from different sources simultaneously. Recycling makes it possible to integrate raw materials out of steadily increasing waste streams back into production processes. Considering stochastic prices for recycled materials, stochastic supply quantities from the recycler and stochastic demand as well as their potential dependencies, we develop a single-period inventory model to derive the order quantities for virgin and recycled raw materials to determine the related costs and to evaluate the effectiveness of the sourcing strategy. We provide managerial insights into the benefits of such a green sourcing approach with recycling and compare this strategy to standard sourcing without recycling. We conduct a full factorial design and a detailed numerical sensitivity analysis on the key input parameters to evaluate the cost savings potential. Furthermore, we consider the effects of correlations between the stochastic parameters. Green sourcing is especially beneficial in terms of cost savings for high demand variability, high prices of virgin raw material and low expected recycling prices as well as for increasing standard deviation of the recycling price. Besides these advantages it also contributes to environmental sustainability as, compared to sourcing without recycling, it reduces the total quantity ordered and, hence, emissions are reduced

Propuesta de gestión de inventarios para mejorar el proceso de abastecimiento, mediante desarrollo de pronósticos y el sistema de revisión periódica en una empresa comercializadora de lubricantes

En el mercado actual, existe una gran cantidad de pymes comerciales que presentan un amplio margen de pérdidas económicas por quiebres de stock, debido al ineficiente proceso de abastecimiento. En otras palabras, las ventas perdidas y los costos adicionales generados al no tener sus productos disponibles en sus almacenes es un escenario crítico en empresas distribuidoras, cuyo valor agregado radica en maximizar su nivel de servicio al cliente. Para resolver este problema, proponemos un sistema que integra el desarrollo de pronósticos y el modelo de inventarios de revisión periódica, ambas herramientas basadas en el marco de trabajo que se plantea teniendo en cuenta modelos de gestión del conocimiento. Los pronósticos realizados, luego de analizar la demanda, sus patrones y elegir el mejor método a utilizar, son antecedentes para desarrollar la gestión de inventarios y sus políticas. Asimismo, la gestión del conocimiento actuará como soporte del sistema integrado al asegurar que el conocimiento adquirido sea sostenible y se mantenga en el tiempo hasta ser renovado. A través de la simulación realizada para nuestro caso de estudio GP Maquinarias S.A.C., una pyme distribuidora de lubricantes, se obtuvieron resultados que indican una reducción del 93% en las pérdidas por desabastecimientos y un aumento del nivel de servicio que pasa de 79% a 91%. Esta propuesta constituye un sistema integrado interesante para ser aplicado como solución para pymes que presentan altos índices de desabastecimiento y carezcan de este tipo de herramientas.In the current market, there is a large number of SMEs that have a large margin of economic losses due to lack of stocks, due to the supply process. In other words, the lost sales and the costs of the services generated by not having their products available in their warehouses is a critical scenario in the distribution companies, whose added value lies in maximizing their level of customer service. To solve this problem, we propose a system that integrates the development of the attention and the model of the inventories of the periodic review, the bases based on the framework of the work. The results, after analyzing the demand, their patterns and choosing the best method to use, are antecedents to develop the management of inventories and their policies. Likewise, knowledge management will act as an integrated support. Through the simulation carried out for our study case GP Maquinarias S.A.C., a SMEs distributor of lubricants, results were obtained that indicate a reduction of 93% in losses due to stock-outs and an increase in the service level that goes from 79% to 91%. This is an integrated system of interest to be applied as a solution for SMEs that have high stock-outs and lack this type of tools.Trabajo de Suficiencia Profesiona