Search results for "Operations Research"
showing 10 items of 1297 documents
ORDINAL MEASUREMENTS WITH INTERVAL CONSTRAINTS IN THE EIA PROCESS FOR SITING A WASTE STORAGE AREA
2009
We describe application of multicriteria decision analysis (MCDA) in the Environmental Impact Assessment (EIA) procedure for siting a waste storage area. The world’s largest biofuel-based combined heat and power (CHP) plant was built in Pietarsaari, Finland. The plant produces certain byproducts, such as flue dust and bottom ash, which need to be processed and stored to prevent releases to the environment. Different storage sites will have different impacts on people, nature, and the economy. Cardinal measurement of the different impacts was considered too costly. Instead, ordinal measurement of all criteria was applied; i.e., experts ranked the alternative storage sites according to each c…
Co2 emissions of French shippers: The roles of delivery frequency and weight, mode choice, and distance
2014
In this article, the authors describe the effects of delivery frequency, mode choice, distance, and shipment weight on the CO₂ emissions of French shippers, taking advantage of a 2004 survey of French shippers (ECHO) which describes the characteristics of 3000 shippers, 10,000 shipments, and 20,000 transport chain legs. Once the energy consumption and CO₂ emissions of every shipment have been computed, they are divided by the corresponding number of ton-kilometers in order to find their carbon intensity (in grams of CO₂ per ton-kilometer). The authors then analyze the latter with respect to a number of selected shipment characteristics: shipment frequency and mode choice (planning choices),…
Energy and CO2 life cycle inventory issues for aluminum based components: The case study of a high speed train window panel
2016
Abstract As materials production and transport are two relevant sectors in terms of global environmental impact, over the last years environmental impact analyses (mainly life cycle based analyses) of material replacing strategies in means of transportation were developed. Life cycle approach allows to consider the light-weighing benefit without neglecting the environmental impact of material production. In the present research energy and CO2 emissions life cycle analysis of a real case study is presented. Industrial data, experimental measurements and literature analysis were used to develop the life cycle analysis of an aluminum window panel to be assembled on an Italian high speed train.…
A Robustness Approach to Reliability
2012
Reliability of products is here regarded with respect to failure avoidance rather than probability of failure. To avoid failures, we emphasize variation and suggest some powerful tools for handling failures due to variation. Thus, instead of technical calculation of probabilities from data that usually are too weak for correct results, we emphasize the statistical thinking that puts the designers focus on the critical product functions. Making the design insensitive to unavoidable variation is called robust design and is handled by (i) identification and classification of variation, (ii) design of experiments to find robust solutions, and (iii) statistically based estimations of proper safe…
Distributed intelligent control of exceptions in reconfigurable manufacturing systems
2003
In order to react to the continuous and unpredictable changes in product demand, in product variety, and in process technologies, reconfigurable manufacturing systems allow quick adjustment of production capacity and functionality by rearranging or changing their modular components. In this kind of system, operation management issues, such as exception handling policies, become more complex since correct reconfiguration strategies have to be selected. This paper explores the potential of the reconfigurability feature to be a basis for the development of new strategies to handle out-of-the-ordinary events in the production process; in particular, maintaining production flow when machine brea…
Decision making in energy planning: The electre multicriteria analysis approach compared to a fuzzy-sets methodology
1998
Every planning activity generally requires to make some choices. After a preliminary analysis of the sector under examination, a forecast of trends of input-output items, the planner must define an action plan voted to arrange all the strategies and specific interventions able to fit demand and supply during the planned time. The redaction of an action plan implies a strong effort in order to synthesize either suggestions coming from the analysis phases either all the constraints linked to technical choices. In the same time, a large number of "external" variables plays a role in orienting decision making. Some of these can be handled by numerical models (economic cost-benefit analyses, mar…
Into the world of e-waste: mobility among e-scrappers in Nigeria
2017
AbstractIn the management of e-waste, mobility of e-scrappers plays a pivotal role, especially in e-waste acquisition and sales of extracted materials. This research examines the relationship between e-scrappers and the locations of their work by analysing the influence of environmental and social factors on their mobility behaviour in Nigeria. A qualitative analysis of video material collected from 29 male e-scrappers in Nigeria between 2014 and 2015 reveals that e-waste has inherent properties that intermittently mobilise e-scrappers to search for recyclable and valuable electronic trash. Applying the new mobilities paradigm and the new materialism theory, we present that e-scrappers’ mob…
Relationship between employee involvement and lean manufacturing and its effect on performance in a rigid continuous process industry
2015
Relationship between employee involvement and lean manufacturing and its effect on performance in a rigid continuous process industry DOI: 10.1080/00207543.2014.975852 Juan A. Marin-Garciaa* & Tomas Bonaviab Received: 1 Aug 2013 Accepted: 30 Sep 2014 Published online: 04 Nov 2014 This research aims to empirically test the effect of employee involvement on lean manufacturing (LM), and the effect of LM on production outcomes. Employee involvement is operationalised through four related variables: empowerment, training, contingent remuneration and communication. The effects are tested by recording management perceptions in a different industrial sector from those usually studied in previous re…
Effects of network market orientation on new ventures' international performance
2013
By combining international entrepreneurship and marketing aspects, this work attempts to emphasise the importance of relational knowledge in international new ventures by studying the influence of network market orientation on the international results obtained by these firms. The results obtained in the comparison with the proposed structural equations model confirm that network market orientation is a determining factor for firms to achieve better international results. This influence is observed both directly and indirectly with the mediating effect on the differentiation– and cost–based competitive advantages developed by INVs.
Collaborative innovation: the decade that radically changed drilling performance
2012
This article sheds light on key factors associated with innovations that are mainly based on experiential learning. The history of a company engaged in the offshore oil and gas industry exemplifies the points: Hitec started out as a small company with limited financial resources, but over a 10-year period, its innovations and improvements radically transformed offshore oil and gas drilling operations. An evolutionary methodological approach is balanced by theoretically informed analysis. A main finding is that customer–supplier interaction was crucial. Hitec's success, crowned by its eventual acquisition by American capital, can be attributed in part to the know-how and technology provided …