Economic lot of purchase in the plywood industry of the Metropolitan Region of Curitiba

Considerando o equilíbrio entre os custos de manutenção de estoques e o de preparação de pedidos de compra, este artigo se propôs a apontar o lote econômico de aquisição do item madeira, matéria-prima da indústria de compensados, e o comparar com as quantidades atualmente praticadas em dez indústrias desse segmento. Para efeito comparativo, estratificou-se a amostra em dois grupos, considerando-se a agregação ou não de valor ao produto final. Concluiu-se que a maioria dessas empresas já pratica quantidades próximas ao lote econômico de compra cujas médias entre as quantidades reais e as calculadas são idênticas. Observou-se, também, igualdade entre as médias dos custos totais de estoque nas duas situações. Embora individualmente a variação entre as quantidades seja de até 110%, a máxima variação entre os custos totais é de apenas 9%, confirmando uma das críticas a essa técnica, ou seja, que modificações no tamanho do lote somente devam ser propostas para diferenças superiores a 50%. O número mensal de pedidos entre o praticado pela amostra e o sugerido pelo LEC difere em 7%. Observou-se que ambos os grupos mantêm comportamentos semelhantes quanto às variações entre a quantidade sugerida pelo LEC e a praticada. Três empresas da amostra, por apresentarem altos custos totais de estoques, são candidatas a rever o tamanho do lote, tendendo à quantidade econômica. Palavras-chave: Logística; lote econômico de compra; custos de estoque; indústria de compensados. Abstract Economic lot of purchase in the plywood industry of the Metropolitan Region of Curitiba. Considering the balance between the costs of maintenance of supplies and of preparation of purchase order, this article points the economic lot of purchase of the item wooden blade, raw material of the industry of plywood and to compare with the amounts currently practiced in ten industries of this segment. For comparative effect, the sample was divided in two groups, considering the aggregation or not of value in the final item. The conclusion is that the majority of these companies already practices amounts close to the economic lot quantity witch averages between the real amounts and the calculated ones are identical. It was also observed, equality among averages of the total costs of supply in the two situations. Although individually the variation among the amounts is 110%, the maximum variation between the total costs is of only 9%, confirming one of critics to this technique, the modifications in the batch size only must be proposals for differences superior to 50%. The monthly number of order between the practiced for the sample and the suggested for the EOQ differs in 7%. It was observed that both the groups keep similar behaviors in relation of the variations between the amount suggested for the EOQ and the practiced. In function of rising of total costs of supplies, three companies of sample are candidates to review these amounts, tending to the economic order quantity.Keyword: Logistic; economical order quantity; costs of supply; industry of plywood.Considering the balance between the costs of maintenance of supplies and of preparation of purchase order, this article points the economic lot of purchase of the item wooden blade, raw material of the industry of plywood and to compare with the amounts currently practiced in ten industries of this segment. For comparative effect, the sample was divided in two groups, considering the aggregation or not of value in the final item. The conclusion is that the majority of these companies already practices amounts close to the economic lot quantity witch averages between the real amounts and the calculated ones are identical. It was also observed, equality among averages of the total costs of supply in the two situations. Although individually the variation among the amounts is 110%, the maximum variation between the total costs is of only 9%, confirming one of critics to this technique, the modifications in the batch size only must be proposals for differences superior to 50%. The monthly number of order between the practiced for the sample and the suggested for the EOQ differs in 7%. It was observed that both the groups keep similar behaviors in relation of the variations between the amount suggested for the EOQ and the practiced. In function of rising of total costs of supplies, three companies of sample are candidates to review these amounts, tending to the economic order quantity