scholarly journals Selection of the Optimal Actions for Crashing Processes Duration to Increase the Robustness of Construction Schedules

2020 ◽  
Vol 10 (22) ◽  
pp. 8028
Author(s):  
Sławomir Biruk ◽  
Piotr Jaśkowski
Keyword(s):  
Time Lag ◽  
Decision Support Tool ◽  
Support Tool ◽  
Schedule Compression ◽  
Simulation Based ◽  
Speed Up ◽  
The Cost ◽  
Construction Schedules ◽  
Optimal Set ◽  
Selection Of

Both the construction clients and the contractors want their projects delivered on time. Construction schedules, usually tight from the beginning, tend to expire as the progress of works is disturbed by materializing risks. As consequence, the project’s original milestones are delayed. To protect the due date and, at the same time, avoid changes to the logic of work, the manager needs to the project progress and, if delays occur, speed up processes not yet completed. The authors investigate the problem of selecting the optimal set of actions of responding to schedule delays. They put forward a simulation-based method of selecting schedule compression measures (speeding up processes) and determining the best moment to take such actions. The idea is explained using a simple case. The results confirm that it is possible to find an easily implementable schedule crashing mode to answer schedule disturbances. The proposed method enables minimizing the cost of schedule crashing actions and the cost of delays as well as increasing the robustness of the schedule by reducing differences between the actual and the as-planned process starts. It is intended as a decision support tool to help construction managers prepare better reactive schedules. The lowest costs are achieved if the acceleration measures are implemented with some time lag to the occurrence of delays.

Economic considerations and decision support tool for wastewater reuse scheme planning

2007 ◽  
Vol 56 (5) ◽  
pp. 175-182 ◽  
Author(s):  
R. Hochstrat ◽  
D. Joksimovic ◽  
T. Wintgens ◽  
T. Melin ◽  
D. Savic
Keyword(s):  
Water Reuse ◽  
Net Present Value ◽  
Wastewater Reuse ◽  
Reclaimed Water ◽  
Decision Support Tool ◽  
Critical Issue ◽  
Economic Feasibility ◽  
Support Tool ◽  
The Cost ◽  
Economic Considerations

The reuse of upgraded wastewater for beneficial uses is increasingly adopted and accepted as a tool in water management. However, funding of schemes is still a critical issue. The focus of this paper is on economic considerations of water reuse planning. A survey of pricing mechanisms for reclaimed water revealed that most schemes are subsidised to a great extent. In order to minimise these state contributions to the implementation and operation of reuse projects, their planning should identify a least cost design option. This also has to take into account the established pricing structure for conventional water resources and the possibility of gaining revenues from reclaimed water pricing. The paper presents a case study which takes into account these aspects. It evaluates different scheme designs with regard to their Net Present Value (NPV). It could be demonstrated that for the same charging level, quite different amounts of reclaimed water can be delivered while still producing an overall positive NPV. Moreover, the economic feasibility and competitiveness of a reuse scheme is highly determined by the cost structure of the conventional water market.

scholarly journals Simulation-Based Decision Support System to Improve Material Flow of a Textile Company

2021 ◽  
Vol 13 (5) ◽  
pp. 2947
Author(s):  
Vítor Silva ◽  
Luís Pinto Ferreira ◽  
Francisco J. G. Silva ◽  
Benny Tjahjono ◽  
Paulo Ávila
Keyword(s):  
Decision Support ◽  
Material Flow ◽  
Control Strategies ◽  
Decision Support Tool ◽  
Raw Material ◽  
Support Tool ◽  
Point Of Entry ◽  
Work Area ◽  
Simulation Based ◽  
Positive Results

To remain competitive, companies must continuously improve the processes at hand, be they administrative, production, or logistics. The objective of the study described in this paper was to develop a decision-making tool based on a simulation model to support the production of knits and damask fabrics. The tool was used to test different control strategies for material flow, from the raw material warehouse to the finished product warehouse, and thus can also be used to evaluate the impacts of these strategies on the productivity. The data upon which the decision support tool was built were collected from five sectors of the plant: the raw material warehouse, knit production, damask production, finishing work, and the finished product warehouse. The decision support tool met the objectives of the project, with all five strategies developed showing positive results. Knit and damask production rates increased by up to 8% and 44%, respectively, and a reduction of 75% was observed in the waiting time on the point of entry to the finishing work area, compared to the company’s existing system.

Transparency Issues Within a Transport Buyer and Provider Relationship

2020 ◽  
pp. 78-95
Author(s):  
Eirill Bø
Keyword(s):  
Supply Chain ◽  
Decision Support ◽  
Decision Support Tool ◽  
Food Distribution ◽  
Household Waste ◽  
Support Tool ◽  
Time Parameters ◽  
The Right ◽  
The Cost ◽  
The Relationship

Transport is an important function in the supply chain. This chapter focuses on how to buy a transport service, how to form a transport contract, and how a transparent relationship will influence the risk and the relationship between transport provider and buyer. By developing a decision support tool (DST-model) and calculating the cost and the time parameters, the right price and the cost drivers will appear. The cases described in this chapter are a large Norwegian wholesaler for food, distribution to the retailer, and two Norwegian municipalities collecting household waste. In these cases, the buyer and the provider are acting blind in setting the transport price. This means that there is a huge risk for either a bankruptcy by the transport provider or an overpriced transport for the buyer.

scholarly journals Cyber Risk Propagation and Optimal Selection of Cybersecurity Controls for Complex Cyberphysical Systems

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1691
Author(s):  
Georgios Kavallieratos ◽  
Georgios Spathoulas ◽  
Sokratis Katsikas
Keyword(s):  
Residual Risk ◽  
Cyberphysical Systems ◽  
Systems Of Systems ◽  
Component Systems ◽  
Autonomous Ship ◽  
The Cost ◽  
Navigational Systems ◽  
Cyber Risk ◽  
Optimal Set ◽  
Selection Of

The increasingly witnessed integration of information technology with operational technology leads to the formation of Cyber-Physical Systems (CPSs) that intertwine physical and cyber components and connect to each other to form systems-of-systems. This interconnection enables the offering of functionality beyond the combined offering of each individual component, but at the same time increases the cyber risk of the overall system, as such risk propagates between and aggregates at component systems. The complexity of the resulting systems-of-systems in many cases leads to difficulty in analyzing cyber risk. Additionally, the selection of cybersecurity controls that will effectively and efficiently treat the cyber risk is commonly performed manually, or at best with limited automated decision support. In this work, we propose a method for analyzing risk propagation and aggregation in complex CPSs utilizing the results of risk assessments of their individual constituents. Additionally, we propose a method employing evolutionary programming for automating the selection of an optimal set of cybersecurity controls out of a list of available controls, that will minimize the residual risk and the cost associated with the implementation of these measures. We illustrate the workings of the proposed methods by applying them to the navigational systems of two variants of the Cyber-Enabled Ship (C-ES), namely the autonomous ship and the remotely controlled ship. The results are sets of cybersecurity controls applied to those components of the overall system that have been identified in previous studies as the most vulnerable ones; such controls minimize the residual risk, while also minimizing the cost of implementation.

scholarly journals A holistic End-of-Life (EoL) Index for the quantitative impact assessment of CFRP waste recycling techniques

2021 ◽  
Vol 8 ◽  
pp. 18
Author(s):  
Dionysios N. Markatos ◽  
Christos V. Katsiropoulos ◽  
Konstantinos I. Tserpes ◽  
Spiros G. Pantelakis
Keyword(s):  
Environmental Impact ◽  
End Of Life ◽  
Volume Fraction ◽  
Decision Support Tool ◽  
Waste Recycling ◽  
Recycling Process ◽  
Support Tool ◽  
Recycled Fibers ◽  
The Cost ◽  
Recycling Techniques

In the present study, a holistic End-of-Life (EoL) Index is introduced to serve as a decision support tool for choosing the optimal recycling process among a number of alternative recycling techniques of CFRP waste. For the choice of the optimal recycling process, quality of the recycled fibers as well as cost and environmental impact of the recycling methods under consideration, are accounted for. Quality is interpreted as the reusability potential of the recycled fibers; that is quantified through the equivalent volume fraction of recycled fibers that balances the mechanical properties of a composite composed of a certain volume fraction of virgin fibers. The proposed Index is offering an estimated balanced score, quantifying a trade-off between the reusability potential of the recycled fibers as well as the cost and the environmental impact of the recycling methods considered.

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