Analysis of the Impact of Changeover Time and Priority Rules on the Timely Execution of Customer Orders

Using cellular automata (CA) Nagel–Schreckenberg (NaSch) model, we numerically study the probability P ac of the occurrence of car accidents at nonsignalized intersection when drivers do not respect the priority rules. We also investigated the impact of mixture lengths and velocities of vehicles on this probability. It is found that in the first case, where vehicles distinguished only by their lengths, the car accidents start to occur above a critical density ρc. Furthermore, the increase of the fraction of long vehicles (FL) delays the occurrence of car accidents (increasing ρc) and increases the risk of collisions when ρ > ρc. In other side, the mixture of maximum velocities (with same length for all vehicles) leads to the appearance of accidents at the intersection even in the free flow regime. Moreover, the increase of the fraction of fast vehicles (Ff) reduces the accident probability (P ac ). The influence of roads length is also studied. We found that the decrease of the roads length enhance the risk of collision.

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Order Quantity Distributions: Estimating an Adequate Aggregation Horizon

Management and Production Engineering Review ◽

10.1515/mper-2016-0024 ◽

2016 ◽

Vol 7 (3) ◽

pp. 39-48 ◽

Cited By ~ 5

Author(s):

Poul Svante Eriksen ◽

Peter Nielsen

Keyword(s):

Aggregate Demand ◽

Order Quantity ◽

Planning And Control ◽

Analytical Perspective ◽

Planning Methods ◽

First Come First Serve ◽

And Control ◽

The Impact ◽

Customer Orders

Abstract In this paper an investigation into the demand, faced by a company in the form of customer orders, is performed both from an explorative numerical and analytical perspective. The aim of the research is to establish the behavior of customer orders in first-come-first-serve (FCFS) systems and the impact of order quantity variation on the planning environment. A discussion of assumptions regarding demand from various planning and control perspectives underlines that most planning methods are based on the assumption that demand in the form of customer orders are independently identically distributed and stem from symmetrical distributions. To investigate and illustrate the need to aggregate demand to live up to these assumptions, a simple methodological framework to investigate the validity of the assumptions and for analyzing the behavior of orders is developed. The paper also presents an analytical approach to identify the aggregation horizon needed to achieve a stable demand. Furthermore, a case study application of the presented framework is presented and concluded on.

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Resource-Constrained Construction Scheduling Using Agent Based Modeling Technique

Journal of Civil Engineering and Construction ◽

10.32732/jcec.2019.8.1.25 ◽

2019 ◽

Vol 8 (1) ◽

pp. 25-33

Author(s):

Ahmed Senouci ◽

Karim Abdel Warith ◽

Neil Eldin

Keyword(s):

Agent Based Modeling ◽

Priority Rules ◽

Resource Constrained ◽

Project Duration ◽

Agent Based ◽

Construction Scheduling ◽

Constrained Problems ◽

Proposed Model ◽

The Impact

This paper presents the use of Agent Based Modeling (ABM) technique as a tool for optimum resource constrained scheduling. The model added two features to the standard resource scheduling applications. It allowed activity interruptions when necessary and the impact of the quality of the predecessors on the successors’ duration. An illustrative example is offered to demonstrate the performance of the proposed model. ABM technique was confirmed to be a valid approach for seeking alternative solutions in resource constrained schedules. The model proved advantageous to resource-constrained schedules. It illustrated additional flexibility to the standard techniques for resource-constrained problems. The model was proven successful in minimizing the project duration under preset priority rules.

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Multi-Criteria Optimization in Operations Scheduling Applying Selected Priority Rules

Applied Sciences ◽

10.3390/app11062783 ◽

2021 ◽

Vol 11 (6) ◽

pp. 2783

Author(s):

Zuzana Červeňanská ◽

Pavel Važan ◽

Martin Juhás ◽

Bohuslava Juhásová

Keyword(s):

Production Control ◽

Job Shop ◽

Discrete Event ◽

Production Performance ◽

Flexible Job Shop ◽

Priority Rule ◽

Priority Rules ◽

En Bloc ◽

Weighted Sum Method ◽

The Impact

The utilization of a specific priority rule in scheduling operations in flexible job shop systems strongly influences production goals. In a context of production control in real practice, production performance indicators are evaluated always en bloc. This paper addresses the multi-criteria evaluating five selected conflicting production objectives via scalar simulation-based optimization related to applied priority rule. It is connected to the discrete-event simulation model of a flexible job shop system with partially interchangeable workplaces, and it investigates the impact of three selected priority rules—FIFO (First In First Out), EDD (Earliest Due Date), and STR (Slack Time Remaining). In the definition of the multi-criteria objective function, two scalarization methods—Weighted Sum Method and Weighted Product Method—are employed in the optimization model. According to the observations, EDD and STR priority rules outperformed the FIFO rule regardless of the type of applied multi-criteria method for the investigated flexible job shop system. The results of the optimization experiments also indicate that the evaluation via applying multi-criteria optimization is relevant for identifying effective solutions in the design space when the specific priority rule is applied in the scheduling operations.

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Formation of Lunar Craters and Bright Rays as a Result of Meteorite Impacts

Symposium - International Astronomical Union ◽

10.1017/s0074180900178404 ◽

1962 ◽

Vol 14 ◽

pp. 415-418

Author(s):

K. P. Stanyukovich ◽

V. A. Bronshten

Keyword(s):

Explosive Charge ◽

The Moon ◽

Meteorite Impacts ◽

The Earth ◽

Lunar Craters ◽

The Impact

The phenomena accompanying the impact of large meteorites on the surface of the Moon or of the Earth can be examined on the basis of the theory of explosive phenomena if we assume that, instead of an exploding meteorite moving inside the rock, we have an explosive charge (equivalent in energy), situated at a certain distance under the surface.

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The Geosciences Applied to Lunar Exploration

Symposium - International Astronomical Union ◽

10.1017/s0074180900178222 ◽

1962 ◽

Vol 14 ◽

pp. 169-257 ◽

Cited By ~ 9

Author(s):

J. Green

Keyword(s):

Lunar Surface ◽

Probable Mechanism ◽

Point Of View ◽

Lunar Exploration ◽

Geological Model ◽

Apply Geophysics ◽

Surface Features ◽

The Impact

The term geo-sciences has been used here to include the disciplines geology, geophysics and geochemistry. However, in order to apply geophysics and geochemistry effectively one must begin with a geological model. Therefore, the science of geology should be used as the basis for lunar exploration. From an astronomical point of view, a lunar terrain heavily impacted with meteors appears the more reasonable; although from a geological standpoint, volcanism seems the more probable mechanism. A surface liberally marked with volcanic features has been advocated by such geologists as Bülow, Dana, Suess, von Wolff, Shaler, Spurr, and Kuno. In this paper, both the impact and volcanic hypotheses are considered in the application of the geo-sciences to manned lunar exploration. However, more emphasis is placed on the volcanic, or more correctly the defluidization, hypothesis to account for lunar surface features.

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Asteroid and Comet Impact Speeds upon Mars: Significance for Panspermia and the Supply of Organics

International Astronomical Union Colloquium ◽

10.1017/s0252921100014718 ◽

1997 ◽

Vol 161 ◽

pp. 197-201 ◽

Cited By ~ 1

Author(s):

Duncan Steel

Keyword(s):

Probability Distributions ◽

Regions Of Interest ◽

Significant Fraction ◽

Organic Chemicals ◽

Impact Speed ◽

The Mean ◽

The Impact

AbstractWhilst lithopanspermia depends upon massive impacts occurring at a speed above some limit, the intact delivery of organic chemicals or other volatiles to a planet requires the impact speed to be below some other limit such that a significant fraction of that material escapes destruction. Thus the two opposite ends of the impact speed distributions are the regions of interest in the bioastronomical context, whereas much modelling work on impacts delivers, or makes use of, only the mean speed. Here the probability distributions of impact speeds upon Mars are calculated for (i) the orbital distribution of known asteroids; and (ii) the expected distribution of near-parabolic cometary orbits. It is found that cometary impacts are far more likely to eject rocks from Mars (over 99 percent of the cometary impacts are at speeds above 20 km/sec, but at most 5 percent of the asteroidal impacts); paradoxically, the objects impacting at speeds low enough to make organic/volatile survival possible (the asteroids) are those which are depleted in such species.

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