This paper addresses the problem faced by a Brazilian oil and gas company of recovering flights for passenger transportation (mainly teams of employees) to maritime units. Due to unexpected events such as bad weather or aircraft mechanical failures, the original timetable very often cannot be fully met, resulting in flight delays on the same day or even postponements to the following days. As a result, the operation of the maritime units and the scheduling of employee shifts are affected to some extent. Based on a case study conducted at the company, we present a detailed continuous-time mixed-integer programming model that aims to include pending flights in the daily scheduling of an aerodrome with a minimum overall delay and usage of aircraft (helicopters), subject to flights with different rescheduling priorities, aerodrome and aircraft time windows, single runways at the aerodrome and single landing spots at each maritime unit, postponement and shift regulations, heterogeneous fleet of helicopters, mandatory stops for the crew to rest and have lunch, among others. We also present a discrete-time simplification of the former model and some simple solution approaches based on these models in order to cope with larger problem instances. The approach performance is assessed using real-life problem instances whose data were collected in the case study, using a general-purpose optimization software. The results show the potential of these approaches in dealing with this short-term flight rescheduling problem.
As atividades logísticas de uma empresa podem ser responsáveis por uma significativa parcela de sua degradação total do meio ambiente. No que toca a poluição atmosférica, isso ocorre principalmente devido à queima de combustível pela sua frota. Em busca de uma Logística Verde, a mensuração de emissões das atividades logísticas pode auxiliar na identificação de ações para diminuir tais emissões. O presente trabalho propôs-se a calcular as emissões de poluentes atmosféricos por veículos automotores de uma frota de uma empresa. Os dados para estudo foram fornecidos pelo histórico de registros da empresa e o método foi adaptado a partir do Relatório de Emissões Veiculares do Estado de São Paulo de 2015. Foi possível mensurar as emissões dos poluentes CO, CO2, NOx (óxidos de nitrogênio), hidrocarbonetos não metano, aldeídos totais e material particulado. Os resultados possibilitaram à empresa uma base de dados para futuros planos de ação para se reduzir as emissões de cada poluente geradas pela atividade de sua frota. Palavras-chave: logística verde, emissões veiculares, emissões atmosféricas XXXVII ENCONTRO NACIONAL DE ENGENHARIA DE PRODUCAO "A Engenharia de Produção e as novas tecnologias produtivas: indústria 4.0, manufatura aditiva e outras abordagens avançadas de produção"
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