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11 – 20 of over 6000Debadyuti Das and Aditya Singh
The present work seeks to determine the optimal delivery schedule of equipment at a project site in the backdrop of limited storage space, at a minimum cost, and without…
Abstract
Purpose
The present work seeks to determine the optimal delivery schedule of equipment at a project site in the backdrop of limited storage space, at a minimum cost, and without disturbing the overall project schedule. In addition, the optimized delivery schedule helps in minimizing the fluctuating requirements of space at the project site across the entire project lifespan.
Design/methodology/approach
The study is carried out at a Steel plant operating in a constrained space but undergoing a production capacity expansion. The problem motivated us to explore the possibility of postponing the delivery dates of certain equipment closer to the erection dates without compromising on the project schedule. Given the versatility of linear programming models in dealing with such schedule optimization problems, the authors formulated the above problem as a Zero-One Integer Linear Programming problem.
Findings
The model is implemented for all the new equipment arriving for two major units – the Hot Strip Mill (HSM) and the Blast Furnace (BF). It generates an optimized delivery schedule by delaying the delivery of some equipment by a certain number of periods, without compromising the overall project schedule and at a minimum storage cost. The average space utilization increases by 25.85 and 14.79% in HSM and BF units respectively. The fluctuations in space requirements are reduced substantially in both units.
Originality/value
The study shows a timeline in the form of a Gantt chart for the delivery of equipment, storage of equipment across different periods, and the number of periods for which the delivery of certain equipment needs to be postponed. The study uses linearly increasing storage costs with the increase in the number of periods for storage of the equipment in the temporary shed.
Highlights
Determined the optimal delivery schedule of the equipment in a project environment in the backdrop of limited storage space in the project site.
Formulated the above problem as a Zero-One Integer Linear Programming (ILP) problem.
The average space utilization has increased by 25.85 and 14.79% in HSM and BF units respectively.
The optimized delivery schedule helps in reducing the fluctuations in space requirements substantially across the entire lifespan of the project.
The timeline of delivery of equipment, storage of equipment across different periods and periods of postponement of the equipment are shown in the form of a Gantt Chart.
Determined the optimal delivery schedule of the equipment in a project environment in the backdrop of limited storage space in the project site.
Formulated the above problem as a Zero-One Integer Linear Programming (ILP) problem.
The average space utilization has increased by 25.85 and 14.79% in HSM and BF units respectively.
The optimized delivery schedule helps in reducing the fluctuations in space requirements substantially across the entire lifespan of the project.
The timeline of delivery of equipment, storage of equipment across different periods and periods of postponement of the equipment are shown in the form of a Gantt Chart.
Details
Keywords
Luciano Costa Santos, Cláudia Fabiana Gohr and Milton Vieira Junior
The paper aims to present a hands‐on activity for operations management (OM) education that simulates assembly operations common in industrial settings using polyvinyl chloride…
Abstract
Purpose
The paper aims to present a hands‐on activity for operations management (OM) education that simulates assembly operations common in industrial settings using polyvinyl chloride (PVC) threadable fittings utilised in water pipes as interchangeable parts for easy manual assembly.
Design/methodology/approach
The teaching method followed the philosophy of active learning and was applied in an action research approach; the proposed activity was tested and improved during applications in the classroom.
Findings
The applicability of the method was proven during in‐class exercises. The results were confirmed with positive feedback from the students involved in the exercises, which was obtained through a survey conducted after a set of applications.
Research limitations/implications
Although the proposed activity may have several possibilities for application, this paper focuses specifically on teaching the topics of work measurement and assembly line balancing, thus limiting the generalisability of these findings to other OM techniques. Therefore, it is important that the activity is further adapted to teach other OM topics.
Practical implications
The activity performed with pipe fittings represents a practical exercise that contributes to reduction of the gap between theory and practice in OM education. Using simple and low cost materials, the students are involved in creating a real process from a fictional product.
Originality/value
This paper presents an experiential learning exercise applied using an innovative approach, using pipe fittings as interchangeable parts assembled in a production line.
Details
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Linet Özdamar, Gündüz Ulusoy and Mete Bayyigit
Considers the resource‐constrained project scheduling problem where cash inflows and outflows are tied to the occurrence of events. The objective is the maximization of the…
Abstract
Considers the resource‐constrained project scheduling problem where cash inflows and outflows are tied to the occurrence of events. The objective is the maximization of the project net present value (NPV) as well as the minimization of project tardiness in the presence of a project due date. Develops hybrid scheduling rules with both NPV and tardiness considerations to enhance both objectives. Experiments extensively with a set of benchmark problems originally designed for the objective of minimizing the project duration. Demonstrates that thje hybrid rules developed here are superior in performance with respect to both objectives when compared with well known rules which are developed for the two objective of minimizing the project duration. Demonstrates that the hybrid rules developed here are superior in performance with respect to both objectives when compared with well‐known rules which are developed for the two objectives taken individually. Furthermore, the iterative algorithm improves the performance of all tested rules significantly.
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David Austen-Smith, Daniel Diermeier and Eitan Zemel
In late 2009 Toyota became the subject of media and U.S. government scrutiny after multiple deaths and injuries were attributed to accidents resulting from the unintended and…
Abstract
In late 2009 Toyota became the subject of media and U.S. government scrutiny after multiple deaths and injuries were attributed to accidents resulting from the unintended and uncontrolled acceleration of its cars. Despite Toyota's voluntary recall of 4.2 million vehicles for floor mats that could jam the accelerator pedal and a later recall to increase the space between the gas pedal and the floor, the company insisted there was no underlying defect and defended itself against media reports and regulatory statements that said otherwise. As the crisis escalated, Toyota was further criticized for its unwillingness to share information from its data recorders about possible problems with electronic throttle controls and sticky accelerator pedals, as well as braking problems with the Prius. By the time Toyota Motor Company president Akio Toyoda apologized in his testimony to the U.S. Congress, Toyota's stock price had declined, in just over a month, by 20 percent---a $35 billion loss of market value.
Understand the strategic and reputational nature of crises Recognize the challenges of managing a crisis Learn the requirements for building trust in a crisis Understand the challenges of managing a crisis that may not be the company's fault Identify the strategic business problem in a crisis Understand how corporate structure may help or hinder effective crisis management Understand the media landscape and its impact on crisis management
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Ministry of Health, Whitehall, S.W.1. 31st July, 1925. SIR, I am directed by the Minister of Health to draw the attention of the Council to the Milk and Dairies (Consolidation…
Abstract
Ministry of Health, Whitehall, S.W.1. 31st July, 1925. SIR, I am directed by the Minister of Health to draw the attention of the Council to the Milk and Dairies (Consolidation) Act, 1915, which will come into operation on the 1st September, 1925. Section 21 (1) of the Act provided that it should come into operation on such date, not being later than the expiration of one year after the termination of the war, as the Local Government Board might by order appoint. Section 1 of the Milk and Dairies (Amendment) Act, 1922, enacted that the 1915 Act, notwithstanding anything contained therein, should not come into operation before the 1st September, 1925. Although it was the evident intention of the 1922 Act that the 1915 Act should come into operation on the date mentioned, the Minister is advised that it is not certain that this is effected automatically by the Act itself. He has therefore deemed it advisable, in order to remove any possible doubt, to make an Order formally appointing the 1st September, 1925, as the date of commencement of the Act.
This study examines whether rules, particular participants, and executive politics in state tax revenue estimation exert measurable influences on forecast error. Fixed-effects…
Abstract
This study examines whether rules, particular participants, and executive politics in state tax revenue estimation exert measurable influences on forecast error. Fixed-effects estimation using data from states’ respective fiscal years 1994 to 2003 indicates that all impact state tax revenue forecast accuracy in varying ways, and results suggest that policy can be crafted to effectively mitigate forecast error. Further examination of the quality of participation in tax revenue forecasting as well as the mechanisms of political involvement in this arena is suggested.