Search results for "Operations"
showing 10 items of 1692 documents
Ergonomic Indicators and Physical Workload Risks in Food Production and Possibilities for Risk Prevention
2021
The food industry is the most important and largest manufacturing industry in Latvia, producing almost a third of all manufacturing output. Employees in a food production enterprises are exposed to a variety of ergonomic risks: monotonous work movements that can be repeated up to 1000 times a day, overloads that exceeds 30 kg in lifting and moving operations, forced working postures, fast work pace. The aim of the study was to identify ergonomic indicators related to physical load for packers in one medium-sized company producing potato starch in Latvia. When summarizing the results of the survey on burden-lifting rates, it should be noted that, in a shift, 30% of packers lift the burden fr…
Economic lot scheduling on multiple production lines with resource constraints
2003
Abstract This paper deals with the multiple production line economic lot scheduling problem, where some items cannot be produced concurrently since they compete for some discrete resources. In particular, cyclic schedules are sought for a problem where identical production lines are present, lost sales are allowed, and minimization of the long-range production, setup, inventory, and shortage penalty costs are required. A heuristic procedure for this problem is introduced, a numerical example is worked out and some computational experiments are presented.
Application and assessment of IDEF3‐process flow description capture method
1995
The IDEF techniques have been developed in projects sponsored by the US Air Force in order to describe, specify and model manufacturing systems in a structured graphical form. These techniques can be classified in two categories: the “modelling” and the “descriptive” varieties. Compares two IDEF methods (one of the modelling type and one of the descriptive type) in order to represent (model or describe) two different aspects of an industrial organization. The methods compared are IDEF0, function modelling method, and IDEF3, process flow description capture method. Concludes that when considering the sequencing of the activities in process, aiming at highlighting their eventual simultaneity,…
Performance analysis of the closed loop supply chain
2012
Purpose The question of resource scarcity and emerging pressure of environmental legislations has brought a new challenge for the manufacturing industry. On the one hand, there is a huge population that demands a large quantity of commodities; on the other hand, these demands have to be met by minimum resources and pollution. Resource conservative manufacturing (ResCoM) is a proposed holistic concept to manage these challenges. The successful implementation of this concept requires cross functional collaboration among relevant fields, and among them, closed loop supply chain is an essential domain. The paper aims to highlight some misconceptions concerning the closed loop supply chain, to d…
Sensitivity analysis of efficiency and Malmquist productivity indices: An application to Spanish savings banks
2008
Hypothesis testing and statistical precision in the context of non-parametric efficiency and productivity measurement have been investigated since the early 1990s. Recent contributions focus on this matter through the use of resampling methods-i.e., bootstrapping techniques. However, empirical evidence is still practically non-existent. This gap is more noticeable in the case of banking efficiency studies, where the literature is immense. In this work, we explore productivity growth and productive efficiency for Spanish savings banks over the (initial) post-deregulation period 1992-1998 using Data Envelopment Analysis (DEA) and bootstrapping techniques. Results show that productivity growth…
Innovative IC framework in the non profit sector
2012
The importance of intellectual capital in the non-profit sector generates the need to measure its role in the value creation process. The purpose of the paper is to study the application of intellectual capital within the non-profit sector, by turning attention to resources such as: knowledge, experience, and skills. Organizations, which are able to increase the knowledge of their staff and transform this knowledge into skills to improve services, can easily meet users’ needs and, thereby, become competitive. This contribution proposes to study how people’s knowledge can contribute to increasing social value, which is the non–profit organization’s aim. Furthermore, the goal is to de…
On the dynamics of eco-efficiency performance in the European Union
2016
This paper evaluates the evolution of environmental performance in the context of the European Union (EU), over the period 1993–2010. The context is particularly relevant, due to the traditionally high concerns of the EU about these issues, which has triggered off several initiatives and regulations on environmental protection. In this setting, we conduct a two-stage analysis which develops environmental performance indicators in the first stage for each pair country-year, and evaluates its evolution in the second. More specifically, in the first stage we estimate specific efficiencies for three air-pollutants (CO2e, SO2, NOx), along with an eco-efficiency indicator, for which we use the sl…
SZACOWANIE CZASU REALIZACJI PROJEKTU PRZY NIEPRECYZYJNYCH ZMIENNYCH
2017
Praca przedstawia istotę i znaczenie problemu szacowania czasu realizacji projektów w warunkach niepewności i ryzyka z zastosowaniem skierowanych liczb rozmytych. W pracy przedstawiono autorskie podejście do szacowania czasu realizacji projektów bazujące na rozmytym modelu niepewności czasów czynności projektowych ze skierowaniem. Zaprezentowana rozszerzona metoda ścieżki krytycznej jest nowym podejściem, które do tej pory nie było prezentowane w takim ujęciu w literaturze tematu. W celu weryfikacji poprawności prezentowanego podejścia przedstawiono przykład obliczeniowy ilustrujący dany problem. Przedstawiono zalety proponowanego podejścia. Podejście to może znaleźć zastosowania w praktyce…
Project Scheduling with Stochastic Activity Interruptions
1999
In this chapter we address the problem of scheduling the activities of a resource-constrained project, some of which may be interrupted by an uncertain amount of time. The resources may be, for example, machines in a jobshop, computers with specialized software packages (as those needed for engineering designs), or highly specialized technicians.
Toward completion of the Earth’s proteome: an update a decade later
2017
Protein databases are steadily growing driven by the spread of new more efficient sequencing techniques. This growth is dominated by an increase in redundancy (homologous proteins with various degrees of sequence similarity) and by the incapability to process and curate sequence entries as fast as they are created. To understand these trends and aid bioinformatic resources that might be compromised by the increasing size of the protein sequence databases, we have created a less-redundant protein data set. In parallel, we analyzed the evolution of protein sequence databases in terms of size and redundancy. While the SwissProt database has decelerated its growth mostly because of a focus on i…