Sequencing CONWIP flow-shops: Analysis and heuristics

In this paper, we address the backlog sequencing problem in a flow-shop controlled by a CON\VIP production control system with the objective to minimise the make span We characterise the problem and analyse its similarities and differences with the permutation flow-shop problem A comparison of same well-known flow-shop heuristics is carried out and a simple and fast dispatching rule is proposed. Regarding the more simple and faster heuristics, the proposed dispatching rule outperforms those commonly used for the permutation flow-shop problem. --Scheduling,Sequencing,Flow-Shop,Constant Work in Process (CONWIP),Heuristics,Dispatching Rules

Reflections on the Translatability of the Notion of Holiness

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The Assassin Bug \u3ci\u3eZelus Luridus\u3c/i\u3e (Heteroptera: Reduviidae) in Michigan\u27s Upper Peninsula

(excerpt) On 17 July 1992, an assassin bug (Zelus luridus Stal) was flushed from the stomach of a smallmouth bass (Micropterus dolomieu) collected in West Long Lake of the University of Notre Dame Environmental Research Center, Gogebic County, Michigan

A computational evaluation of constructive and improvement heuristics for the blocking flow shop to minimize total flowtime

This paper focuses on the blocking flow shop scheduling problem with the objective of total flowtime minimisation. This problem assumes that there are no buffers between machines and, due to its application to many manufacturing sectors, it is receiving a growing attention by researchers during the last years. Since the problem is NP-hard, a large number of heuristics have been proposed to provide good solutions with reasonable computational times. In this paper, we conduct a comprehensive evaluation of the available heuristics for the problem and for related problems, resulting in the implementation and testing of a total of 35 heuristics. Furthermore, we propose an efficient constructive heuristic which successfully combines a pool of partial sequences in parallel, using a beam-search-based approach. The computational experiments show the excellent performance of the proposed heuristic as compared to the best-so-far algorithms for the problem, both in terms of quality of the solutions and of computational requirements. In fact, despite being a relative fast constructive heuristic, new best upper bounds have been found for more than 27% of Taillard’s instances.Ministerio de Ciencia e Innovación DPI2013-44461-P/DP

Available-to-promise (ATP) systems: a classification and framework for analysis

Available-to-promise (ATP) systems deal with a number of managerial decisions related to order capture activities in a company, including order acceptance/rejection, due date setting, and resource scheduling. These different but interrelated decisions have often been studied in an isolated manner, and, to the best of our knowledge, no framework has been presented to integrate them into the broader perspective of order capture. This paper attempts to provide a general framework for ATP-related decisions. By doing so, we: (1) identify the different decision problems to be addressed; (2) present the different literature-based models supporting related decisions into a coherent framework; and (3) review the main contributions in the literature for each one of these. We first describe different approaches for order capture available in the literature, depending on two parameters related to the application context of ATP systems, namely the inclusion of explicit information about due dates in the decision model, and the level of integration among decisions. According to these parameters, up to six approaches for ATP-related decisions are identified. Secondly, we show the subsequent decision problems derived from the different approaches, and describe the main issues and key references involving each one of these decision problems. Finally, a number of conclusions and future research lines are discussed.Ministerio de Ciencia e Innovación DPI2007-6134

Linking Scheduling Criteria to Shop Floor Performance in Permutation Flowshops

The goal of manufacturing scheduling is to allocate a set of jobs to the machines in the shop so these jobs are processed according to a given criterion (or set of criteria). Such criteria are based on properties of the jobs to be scheduled (e.g., their completion times, due dates); so it is not clear how these (short-term) criteria impact on (long-term) shop floor performance measures. In this paper, we analyse the connection between the usual scheduling criteria employed as objectives in flowshop scheduling (e.g., makespan or idle time), and customary shop floor performance measures (e.g., work-in-process and throughput). Two of these linkages can be theoretically predicted (i.e., makespan and throughput as well as completion time and average cycle time), and the other such relationships should be discovered on a numerical/empirical basis. In order to do so, we set up an experimental analysis consisting in finding optimal (or good) schedules under several scheduling criteria, and then computing how these schedules perform in terms of the different shop floor performance measures for several instance sizes and for different structures of processing times. Results indicate that makespan only performs well with respect to throughput, and that one formulation of idle times obtains nearly as good results as makespan, while outperforming it in terms of average cycle time and work in process. Similarly, minimisation of completion time seems to be quite balanced in terms of shop floor performance, although it does not aim exactly at work-in-process minimisation, as some literature suggests. Finally, the experiments show that some of the existing scheduling criteria are poorly related to the shop floor performance measures under consideration. These results may help to better understand the impact of scheduling on flowshop performance, so scheduling research may be more geared towards shop floor performance, which is sometimes suggested as a cause for the lack of applicability of some scheduling models in manufacturing

Paper Session III-B - European Node 2 and 3 Space Station Contributions

The International Space Station requires three Nodes for the completion of the configuration. The first of these Nodes, designed and manufactured under National Aeronautics & Space Administration (NASA) contract, has already been launched successfully and is waiting for the assembly of further elements. As a little background, Nodes 2 & 3 were agreed to be designed and constructed in Europe in a Barter agreement between NASA and the European Space Agency (ESA) with the overall management assigned to the Italian Space Agency (ASI). Alenia Spazio (ALS) was awarded the overall prime contractor role. Necessitated by geographical return reasons within ESA programs, subsystem activities were given outside Italy even though this did not adhere to the classical role of prime contractor functions in an optimized standard program. With OHB-System winning the two major sub-contractor roles for the Secondary Structure and the Harness, we are now responsible for designing, manufacturing, and testing these subsystems for Nodes 2 & 3 in an international team approach

Manipulation und Analyse der Topographie von Proteinstrukturen in Flüssigkeit mit dem Rasterkraftmikroskop

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Pengaruh Motivasi dan Kemampuan Serta Komitmen terhadap Kinerja Pengurus Upk PNPM Mandiri Perdesaan di Kabupaten Lumajang

This study aims to determine the influence of motivation and ability and commitment as well as simultaneous and partial view of the dominant of the Performance Management UPK PNPM Mandiri Rural In Lumajang of 60 respondents. The hypothesis in this study is the motivation and the ability and commitment to simultaneously have a significant effect on the performance committee UPK PNPM Mandiri Rural on Lumajang. Motivation and the ability and commitment partially significant effect on the performance committee UPK PNPM Mandiri Rural DistrictLumajang.Variabel motivation dominant influence on the performance committee UPK PNPM Mandiri Rural on Lumajang. The results of this study indicate: 1). Fcount value of 18.274 while the value of 2.769431 Ftable with probability = 0.000 when compared then Fcount > Ftable with α Ttable and a significance level of α β3> β2 thus dominant influence motivational variables on performance.This quantitative study provides an overview of the importance of motivation and the ability and commitment to improving employee performance. If the motivation and the ability and commitment to get less attention then it will be a decrease in employee performance