Optimized crew selection for scheduling of repetitive projects

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mohammadjavad Arabpour Roghabadi ◽  
Osama Moselhi
Keyword(s):  
Design Methodology ◽  
Multi Objective Optimization ◽  
Project Cost ◽  
Content Type ◽  
Project Duration ◽  
Work Interruptions ◽  
Productivity Rate ◽  
Selection For ◽  
Interruption Costs ◽  
Repetitive Activities

PurposeThe purpose of this paper is to identify optimum crew formations at unit execution level of repetitive projects that minimize project duration, project cost, crew work interruptions and interruption costs, simultaneously.Design/methodology/approachThe model consists of four modules. The first module quantifies uncertainties associated with the crew productivity rate and quantity of work using the fuzzy set theory. The second module identifies feasible boundaries for activity relaxation. The third module computes direct cost, indirect cost and interruption costs, including idle crew cost as well as mobilization and demobilization costs. The fourth module identifies near-optimum crew formation using a newly developed multi-objective optimization model.FindingsThe developed model was able to provide improvements of 0.2, 16.86 and 12.98% for minimization of project cost, crew work interruptions and interruption costs from US$1,505,960, 8.3 days and US$8,300, as recently reported in the literature, to US$1,502,979, 6.9 days and US$7,222, respectively, without impacting the optimized project duration.Originality/valueThe novelty of this paper lies in its activity-relaxation free float that considers the effect of postponing early finish dates of repetitive activities on crew work interruptions. The introduced new float allows for calculating the required crew productivity rate that minimizes crew work interruptions without delaying successor activities and without impacting the optimized project duration. It safeguards against assignment of unnecessary costly resources.

Multi-objective optimization for repetitive scheduling under uncertainty

2019 ◽  
Vol 26 (7) ◽  
pp. 1294-1320 ◽  
Author(s):  
Tarek Salama ◽  
Osama Moselhi
Keyword(s):  
Cost Optimization ◽  
Indirect Costs ◽  
Optimization Method ◽  
Multi Objective Optimization ◽  
Software Module ◽  
Content Type ◽  
Project Duration ◽  
Multi Objective ◽  
Work Interruptions ◽  
Cost Calculations

Purpose The purpose of this paper is to present a newly developed multi-objective optimization method for the time, cost and work interruptions for repetitive scheduling while considering uncertainties associated with different input parameters. Design/methodology/approach The design of the developed method is based on integrating six modules: uncertainty and defuzzification module using fuzzy set theory, schedule calculations module using the integration of linear scheduling method (LSM) and critical chain project management (CCPM), cost calculations module that considers direct and indirect costs, delay penalty, and work interruptions cost, multi-objective optimization module using Evolver © 7.5.2 as a genetic algorithm (GA) software, module for identifying multiple critical sequences and schedule buffers, and reporting module. Findings For duration optimization that utilizes fuzzy inputs without interruptions or adding buffers, duration and cost generated by the developed method are found to be 90 and 99 percent of those reported in the literature, respectively. For cost optimization that utilizes fuzzy inputs without interruptions, project duration generated by the developed method is found to be 93 percent of that reported in the literature after adding buffers. The developed method accelerates the generation of optimum schedules. Originality/value Unlike methods reported in the literature, the proposed method is the first multi-objective optimization method that integrates LSM and the CCPM. This method considers uncertainties of productivity rates, quantities and availability of resources while utilizing multi-objective GA function to minimize project duration, cost and work interruptions simultaneously. Schedule buffers are assigned whether optimized schedule allows for interruptions or not. This method considers delay and work interruption penalties, and bonus payments.

Study on pedestrian flow evacuation with individual-guidance mechanism

Kybernetes ◽  
2016 ◽  
Vol 45 (5) ◽  
pp. 772-787 ◽  
Author(s):  
Can Zhong Yao ◽  
Xiao Feng Liu ◽  
Ji Nan Lin
Keyword(s):  
Random Walk ◽  
Majority Rule ◽  
Design Methodology ◽  
Pedestrian Flow ◽  
Content Type ◽  
Optimal Ratio ◽  
Selection For

Purpose – The purpose of this paper is to provide the possible and better selection for pedestrian flow evacuation. Design/methodology/approach – Simulation. Findings – First, according to the model with self-decision agents, the paper figures out that the effect of evacuation guided by the random-walk mechanism exceeds that guided by the inertial mechanism, and specifically, the effect of evacuation could significantly improve if random-walk agents restraint the probability of random walk under 0.4. Besides, on neighborhood reference mechanism, individuals who take neighbors’ average direction as reference tend to achieve better effect of evacuation than that of following majority rule. Furthermore, this paper proposes that an optimal ratio of the proportion of clever individuals and system density exists for evacuation effect improvement. Finally, the evacuating effect with barrier locating in different space is also studied in our research. Originality/value – The effect of evacuation could significantly improve if random-walk agents restraint the probability of random walk under 0.4. On neighborhood reference mechanism, individuals who take neighbors’ average direction as reference tend to achieve better effect of evacuation than that of following majority rule.

DC-link voltage selection for a multi-MW wind turbine

2014 ◽  
Vol 33 (5) ◽  
pp. 1722-1740
Author(s):  
Poopak Roshanfekr ◽  
Torbjörn Thiringer ◽  
Sonja Lundmark ◽  
Mikael Alatalo
Keyword(s):  
Wind Turbine ◽  
Energy Efficient ◽  
Design Methodology ◽  
Synchronous Generators ◽  
Maximum Torque ◽  
Voltage Level ◽  
Content Type ◽  
Permanent Magnet Synchronous Generators ◽  
Selection For ◽  
Maximum Torque Per Ampere

Purpose – The purpose of this paper is to investigate how the dc-link voltage for the converter of a wind generator should be selected, i.e. to determine the losses in the generator and the converter when using various dc-link voltage levels. Design/methodology/approach – To presents the efficiency evaluation of 5 MW wind turbine generating systems, two 5 MW surface mounted permanent magnet synchronous generators (PMSG) with medium and low rated voltage is designed. A two-level transistor converter is considered for ac/dc conversion. Three different dc-link voltage levels are used. By using these voltage levels the PMSG is utilized in slightly different ways. Findings – It is found that the system with the lower voltage machine has slightly higher annual energy efficiency compare to the higher voltage system. Furthermore, it is shown that the best choice for the dc-link voltage level is a voltage between the minimum voltage which gives the desired torque and the voltage which gives Maximum Torque Per Ampere. Originality/value – A procedure as well as investigations with quantified results on how to find the highest complete drive system efficiency for a wind turbine application. Based on two given PMSG, the most energy-efficient dc-link voltage has been established.

Sensory inputs in tourists’ nightlife experiences – a study of Bangkok, Kuala Lumpur and Singapore

2020 ◽  
Vol 14 (2) ◽  
pp. 259-272
Author(s):  
Bình Nghiêm-Phú
Keyword(s):  
Design Methodology ◽  
Kuala Lumpur ◽  
Content Type ◽  
Sensory Inputs ◽  
Tourist Destinations ◽  
Bivariate Correlation ◽  
Sensory Marketing ◽  
Visual Inputs ◽  
Selection For ◽  
Practical Implications

Purpose This study aims to identify the sensory inputs that tourists use to shape their nightlife experiences. Design/methodology/approach The situations in three Southeast Asian cities, Bangkok, Kuala Lumpur and Singapore were examined, using tourist reviews posted on tripadvisor.com. A total of 460 data units concerning Bangkok, 373 data units concerning Kuala Lumpur and 453 data units concerning Singapore were compiled and manually analyzed to reveal the frequency of the primary sensory inputs used by the reviewers. Bivariate correlation analysis was additionally performed to reveal the co-occurrences of the sensory inputs that tourists used to form their impressions of each city. Findings The findings suggest that gustatory inputs were powerful yet unspecific, while visual inputs were vivid and conspicuous. Audio inputs added certain meaningful contributions to some extent for some tourists. However, the distribution of the sensory inputs differed across the three cities. Moreover, the contributions of the olfactory and tactile inputs are largely missing. Practical implications With the management of nightlife businesses (small or micro servicescapes), a thoughtful selection for the drink menu is necessary. When possible, a signature drink should be invented and promoted for each place. With the projection and promotion of tourist destinations as nightlifescapes, a sensory marketing approach should be considered. For example, nightlifescapes could be presented and promoted with unique drinks, good views of the city’s landmarks and interesting local music. Originality/value Prior to this study, little research has been carried out to investigate tourists’ nightlife experiences and their impressions of nightlifescapes. In addition, little has been done to identify the sensory inputs that tourists use to explain their experiences and impressions.

Work continuity constraints in repetitive project scheduling considering soft logic

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Xin Zou ◽  
Guangchuan Wu ◽  
Qian Zhang
Keyword(s):  
Programming Model ◽  
Mixed Integer ◽  
Future Research ◽  
Small Scale ◽  
Content Type ◽  
Project Duration ◽  
Additional Information ◽  
Work Interruptions ◽  
Conflicting Objectives ◽  
Soft Logic

PurposeRepetitive projects play an important role in the construction industry. A crucial point in scheduling this type of project lies in enabling timely movement of crews from unit to unit so as to minimize the adverse effect of work interruptions on both time and cost. This paper aims to examine a repetitive scheduling problem with work continuity constraints, involving a tradeoff among project duration, work interruptions and total project cost (TPC). To enhance flexibility and practicability, multi-crew execution is considered and the logic relation between units is allowed to be changed arbitrarily. That is, soft logic is considered.Design/methodology/approachThis paper proposes a multi-objective mixed-integer linear programming model with the capability of yielding the optimal tradeoff among three conflicting objectives. An efficient version of the e-constraint algorithm is customized to solve the model. This model is validated based on two case studies involving a small-scale and a practical-scale project, and the influence of using soft logic on project duration and total cost is analyzed via computational experiments.FindingsUsing soft logic provides more flexibility in minimizing project duration, work interruptions and TPC, especial for non-typical projects with a high percentage of non-typical activities.Research limitations/implicationsThe main limitation of the proposed model fails to consider the learning-forgetting phenomenon, which provides space for future research.Practical implicationsThis study assists practitioners in determining the “most preferred” schedule once additional information is provided.Originality/valueThis paper presents a new soft logic-based mathematical programming model to schedule repetitive projects with the goal of optimizing three conflicting objectives simultaneously.

Project buffer sizing and dynamic buffer consumption algorithm in power generation construction

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shakib Zohrehvandi ◽  
Mohammad Khalilzadeh ◽  
Maghsoud Amiri ◽  
Shahram Shadrokh
Keyword(s):  
Power Generation ◽  
Heuristic Algorithm ◽  
Completion Time ◽  
Design Methodology ◽  
The Other ◽  
Wind Power Plant ◽  
Content Type ◽  
Project Duration ◽  
Project Completion ◽  
Buffer Sizing

PurposeThe aim of this research is to propose a buffer sizing and buffer controlling algorithm (BSCA) as a heuristic algorithm for calculating project buffer and feeding buffers as well as dynamic controlling of buffer consumption in different phases of a wind power plant project in order to achieve a more realistic project duration.Design/methodology/approachThe BSCA algorithm has two main phases of planning and buffer sizing and construction and buffer consumption. Project buffer and feeding buffers are determined in the planning and buffer sizing phase, and their consumption is controlled in the construction and buffer consumption phase. The heuristic algorithm was coded and run in MATLAB software. The sensitivity analysis was conducted to show the BSCA influence on project implementation. Then, to evaluate the BSCA algorithm, inputs from this project were run through several algorithms recently presented by researchers. Finally, the data of 20 projects previously accomplished by the company were applied to compare the proposed algorithm.FindingsThe results show that BSCA heuristic algorithm outperformed the other algorithms as it shortened the projects' durations. The average project completion time using the BSCA algorithm was reduced by about 15% compared to the previous average project completion time.Originality/valueThe proposed BSCA algorithm determines both the project buffer and feeding buffers and simultaneously controls their consumption in a dynamic way.

Optimizing the scheduling of crew deployments in repetitive construction projects under uncertainty

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Abbas Hassan ◽  
Khaled El-Rayes ◽  
Mohamed Attalla
Keyword(s):  
Construction Projects ◽  
Design Methodology ◽  
Real Life ◽  
Stochastic Scheduling ◽  
Content Type ◽  
Project Duration ◽  
Trade Offs ◽  
Original Contribution ◽  
Novel Model ◽  
Scheduling Technique

PurposeThis paper presents the development of a novel model for optimizing the scheduling of crew deployments in repetitive construction projects while considering uncertainty in crew production rates.Design/methodology/approachThe model computations are performed in two modules: (1) simulation module that integrates Monte Carlo simulation and a resource-driven scheduling technique to calculate the earliest crew deployment dates for all activities that fully comply with crew work continuity while considering uncertainty; and (2) optimization module that utilizes genetic algorithms to search for and identify optimal crew deployment plans that provide optimal trade-offs between project duration and crew deployment plan cost.FindingsA real-life example of street renovation is analyzed to illustrate the use of the model and demonstrate its capabilities in optimizing the stochastic scheduling of crew deployments in repetitive construction projects.Originality/valueThe original contribution of this research is creating a novel multiobjective stochastic scheduling optimization model for both serial and nonserial repetitive construction projects that is capable of identifying an optimal crew deployment plan that simultaneously minimizes project duration and crew deployment cost.

Grey wolf optimization based parameter selection for support vector machines

2016 ◽  
Vol 35 (5) ◽  
pp. 1513-1523 ◽  
Author(s):  
Sathish Eswaramoorthy ◽  
N. Sivakumaran ◽  
Sankaranarayanan Sekaran
Keyword(s):  
Design Methodology ◽  
Support Vector ◽  
Svm Classifier ◽  
Grey Wolf Optimizer ◽  
Grey Wolf ◽  
Grey Wolf Optimization ◽  
Content Type ◽  
Vector Machines ◽  
Human Perceptions ◽  
Selection For

Purpose The purpose of this paper is to tune support vector machine (SVM) classifier using grey wolf optimizer (GWO). Design/methodology/approach The schema of the work aims at extracting the features from the collected data followed by a SVM classifier and metaheuristic optimization to tune the classifier parameters. Findings The optimal tuning of classifier parameters lowers errors due to manual elucidation and decreases the risk in human perceptions and repeated visual dignosis. Originality/value A novel, GWO based tuning algorithm is used for SVM classifier, which is implemented in classifying the complex and nonlinear biomedical signals like intracranial electroencephalogram.

Design and control of electrotechnological systems

2019 ◽  
Vol 39 (1) ◽  
pp. 239-247
Author(s):  
Yuliya Pleshivtseva ◽  
Edgar Rapoport ◽  
Bernard Nacke ◽  
Alexander Nikanorov ◽  
Paolo Di Barba ◽  
...  
Keyword(s):  
Design Methodology ◽  
Quality Criteria ◽  
Objective Functions ◽  
Multi Objective Optimization ◽  
Nsga Ii ◽  
Content Type ◽  
Electromagnetic Devices ◽  
Design Variables ◽  
And Control ◽  
Standard Genetic Algorithm

Purpose This paper aims to investigate different multi-objective optimization (MOO) approaches for design and control of electromagnetic devices. The main goal of MOO is to find the set of design variables or control parameters which will provide the best possible values of typical conflicting objective functions. Design/methodology/approach In the research studies, standard genetic algorithm (GA), non-dominated sorting GA (NSGA-II), migration NSGA algorithm and alternance method of optimal control theory are discussed and compared. Findings The test practical problems of multi-criteria optimization of induction heating processes with respect to chosen quality criteria confirm the effectiveness of application of considered MOO approaches both for the problems of design and control. Originality/value This paper represents and investigates different MOO approaches for design and control of electrotechnological systems.

A partner selection model for collaborative product innovation from the viewpoint of knowledge collaboration

Kybernetes ◽  
2019 ◽  
Vol 49 (6) ◽  
pp. 1623-1644 ◽  
Author(s):  
Jie Jian ◽  
Milin Wang ◽  
Lvcheng Li ◽  
Jiafu Su ◽  
Tianxiang Huang
Keyword(s):  
Optimization Model ◽  
Product Innovation ◽  
Partner Selection ◽  
Multi Objective Optimization ◽  
Content Type ◽  
Multi Objective ◽  
Proposed Model ◽  
Np Hard Problem ◽  
Selection For ◽  
Knowledge Collaboration

Purpose Selecting suitable and competent partners is an important prerequisite to improve the performance of collaborative product innovation (CPI). The purpose of this paper is to propose an integrated multi-criteria approach and a decision optimization model of partner selection for CPI from the perspective of knowledge collaboration. Design/methodology/approach First, the criteria for partner selection are presented, considering comprehensively the knowledge matching degree of the candidates, the knowledge collaborative performance among the candidates, and the overall expected revenue of the CPI alliance. Then, a quantitative method based on the vector space model and the synergetic matrix method is proposed to obtain a comprehensive performance of candidates. Furthermore, a multi-objective optimization model is developed to select desirable partners. Considering the model is a NP-hard problem, a non-dominated sorting genetic algorithm II is developed to solve the multi-objective optimization model of partner selection. Findings A real case is analyzed to verify the feasibility and validity of the proposed model. The findings show that the proposed model can efficiently select excellent partners with the desired comprehensive attributes for the formation of a CPI alliance. Originality/value Theoretically, a novel method and approach to partner selection for CPI alliances from a knowledge collaboration perspective is proposed in this study. In practice, this paper also provides companies with a decision support and reference for partner selection in CPI alliances establishment.

Sign in / Sign up

Export Citation Format

Share Document