scholarly journals Priority Scheduling in the Planning of Multiple-Structure Construction Projects

2017 ◽  
Vol 63 (4) ◽  
pp. 21-33 ◽  
Author(s):  
E. Radziszewska-Zielina ◽  
B. Sroka
Keyword(s):  
Linear Programming ◽  
Computer Program ◽  
Construction Projects ◽  
Programming Model ◽  
Construction Site ◽  
Priority Scheduling ◽  
Ranking List ◽  
Multiple Structure ◽  
Proposed Model ◽  
Interactive Scheduling

AbstractThe paper presents a method of priority scheduling that is useful during the planning of multiple-structure construction projects. This approach is an extension of the concept of interactive scheduling. In priority scheduling, it is the planner that can determine how important each of the technological and organisational constraints are to them. A planner’s preferences can be defined through developing a ranking list that defines which constraints are the most important, and those whose completion can come second. The planner will be able to model the constraints that appear at a construction site more flexibly. The article presents a general linear programming model of the planning of multiple-structure construction projects, as well as various values of each of the parameters that allow us to obtain different planning effects. The proposed model has been implemented in a computer program and its effectiveness has been presented on a calculation example.

scholarly journals Planning repetitive construction projects considering technological constraints

2018 ◽  
Vol 8 (1) ◽  
pp. 500-505 ◽  
Author(s):  
Elżbieta Radziszewska-Zielina ◽  
Bartłomiej Sroka
Keyword(s):  
Construction Projects ◽  
Construction Site ◽  
Priority Scheduling ◽  
Technological Constraints ◽  
Site Manager ◽  
High Degree

Abstract Recently, there has been a growing number of construction projects that require more than one structure to be built - repetitive construction projects. These repetitive construction projects are characterized by a high degree of complexity both in terms of organisational and technological dependencies. A method is needed that will flexibly take into account the technological constraints that occur during the carrying out of repetitive construction projects. The article presents a method of priority scheduling that takes into account technological pauses that can prove useful in the planning of repetitive construction projects. The planner (usually a construction site manager) will be able to model the technological constraints occurring on the construction site in a more flexible way. The article also presents a calculation example in which the application of the developed model has been presented. The developed model proved to be effective in scheduling repetitive construction projects, taking into account technological constraints.

Optimizing Supply and Demand in Coal Logistics Networks

2014 ◽  
Vol 587-589 ◽  
pp. 2007-2013
Author(s):  
Xiao Jun Guan ◽  
Xi Fu Wang ◽  
Hao Kun Fan ◽  
Wan Jing Wu
Keyword(s):  
Linear Programming ◽  
Optimization Problem ◽  
Programming Model ◽  
Supply And Demand ◽  
Actual Situation ◽  
Capacity Limits ◽  
Logistics Networks ◽  
South West ◽  
Proposed Model ◽  
Programming Software

China has a "North coal to south, West coal to east" overall pattern of coal transportation. This paper focuses on how to optimize the distribution of supply and demand, which can effectively reduce the total transportation costs. In order to study the optimization problem, we build a linear programming model, and solve it through commonly used mathematical programming software CPLEX. Then, taking Shanxi as an example, the proposed model was verified. By introducing supply point capacity limits, make our model more adaptable to the actual situation.

The Application of Table Operations Method in Earthwork Blending

2012 ◽  
Vol 204-208 ◽  
pp. 463-466
Author(s):  
Hong Hao Wan ◽  
Ting Hua Xu
Keyword(s):  
Linear Programming ◽  
Operations Research ◽  
Construction Projects ◽  
Programming Model ◽  
Balance Sheet ◽  
Economic Benefits ◽  
Closed Circuit ◽  
Minimum Element ◽  
Operation Method ◽  
Cut And Fill

According to linear programming model of operations research, the paper optimized blending scheme of earthwork by using table operation method. List the earthwork cut and fill balance sheet, through the calculation of excavation and backfill area quantity. Determine the initial transportation scheme with minimum element method, and optimize the scheme with closed circuit method, then get the minimum amount of earthwork blending scheme. It could bring better economic benefits in construction projects by using the table operation method.

Dynamic Disassembly Planning for Remanufacturing of Multiple Types of Products

2010 ◽  
Author(s):  
Changmuk Kang ◽  
Yoo S. Hong
Keyword(s):  
Linear Programming ◽  
End Of Life ◽  
Programming Model ◽  
Cost Minimization ◽  
New Products ◽  
Variable Level ◽  
Proposed Model ◽  
Return Flows ◽  
Disassembly Plan ◽  
Disassembly Planning

With the increased need for remanufacturing of end-of-life products, achieving economic efficiency in remanufacturing is urgently needed. The purpose of this study was to devise a cost-minimization plan for disassembly and remanufacturing of end-of-life products returned by consumers. A returned end-of-life product is disassembled into remanufacturable parts, which are supposed to be used for new products after being remanufactured. Each end-of-life product is disassembled into parts at variable levels as needed, taking into account not only disassembly but also manufacturing, remanufacturing, and holding inventory of remanufacturable parts. This study proposes a linear programming model for derivation of the optimal disassembly plan for each returned product, under deterministically known demand and return flows. For the purposes of an illustrative example, the proposed model was applied to the formulation of an optimal disassembly and remanufacturing plan of ‘Fuser Assembly’ of laser printers. The solution reveals that variable-level disassembly of products saves a significant remanufacturing cost compared with full disassembly.

A Mixed-Integer Linear Programming Model of Closed Loop Supply Chain Network for Manufacturing System

2018 ◽  
Vol 35 ◽  
pp. 198-207 ◽  
Author(s):  
S. Nallusamy ◽  
K. Balakannan ◽  
P.S. Chakraborty ◽  
Gautam Majumdar
Keyword(s):  
Linear Programming ◽  
Supply Chain ◽  
Mixed Integer Linear Programming ◽  
Closed Loop ◽  
Programming Model ◽  
Mixed Integer ◽  
Order Quantity ◽  
Integer Linear Programming Model ◽  
Proposed Model ◽  
Fixed Order

In the present scheme of things, in a manufacturing industry inventory is pitched as one of the significant resources that require to be handled effectively. The aim of this research article is to develop a mixed-integer linear programming model to configure the closed loop supply chain (CLSC) network and that could be optimized for maximizing the profit by determining the fixed order quantity inventory policy in various sites at multiple periods. The objective is to maximize the profit through CLSC by determining the optimal inventory of product and part mix during multiple periods. In onward supply chain, a standard inventory policy is followed when the product moves from manufacturer to end user, but it is very difficult to manage the inventory in the reverse supply chain of the product with the same standard policy. The proposed model examines the standard policy of fixed order quantity by considering three major types of return-recovery pair such as, commercial returns, end-of-use returns, end-of-life returns and their inventory positioning at multiple periods. Raw material supplier, manufacturer, distributer, retailer, customers and for major returns-collection sites like repair site, disassembly site, recycling site and disposal site were included in the network to develop this CLSC network model. The proposed model to configure the CLSC network has been solved by using IBM ILOG CPLEX OPL studio and the results of the model were analysed with numerical investigations followed by sensitivity analysis.

scholarly journals Cross-docks scheduling with multiple doors using fuzzy approach

2020 ◽  
Vol 79 (ET.2020) ◽  
pp. 1-18
Author(s):  
Mitra Movassaghi
Keyword(s):  
Linear Programming ◽  
Objective Function ◽  
Programming Model ◽  
Linear Programming Model ◽  
Mixed Integer ◽  
Non Linear Programming ◽  
Cross Docking ◽  
Proposed Model ◽  
Delivery Routes ◽  
Programming Techniques

One of the most important practices in logistics is Cross-Docking which sets its goals as inventory reduction and customer satisfaction increase. Customers receive goods through docks. Docks are responsible to provide a place for goods before being delivered to the customers. Then, these materials are directly loaded into outbound trucks with little or no storage in between to send to customers in the shortest possible time. This paper is mainly aimed at introducing a mixed integer, non-linear programming model to solve scheduling several cross-docking problems. The proposed model is highly facilitated to allocate the most optimal destinations to storage doors and truck scheduling in docks while selecting the collection and delivery routes. Using optimization approaches at uncertainty conditions is also of great importance. Mathematical programming techniques vividly fail to solve transportation problems that include fuzzy objective function coefficients. A fuzzy multi-objective linear programming model is proposed to solve the transportation decision-making with fuzzy objective function coefficients.

A Linear Programming Model for Product Mix Profit Maximization in A Small Medium Enterprise Company

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
S Mohd Baki ◽  
Jack Kie Cheng
Keyword(s):  
Linear Programming ◽  
Production Planning ◽  
Business Performance ◽  
Programming Model ◽  
Profit Maximization ◽  
Optimal Level ◽  
Linear Programming Model ◽  
Product Mix ◽  
Small Medium Enterprises ◽  
Medium Enterprises

Production planning is often challenging for small medium enterprises (SMEs) company. Most of the SMEs are having difficulty in determining the optimal level of the production output which can affect their business performance. Product mix optimization is one of the main key for production planning. Many company have used linear programming model in determining the optimal combination of various products that need to be produced in order to maximize profit. Thus, this study aims for profit maximization of a SME company in Malaysia by using linear programming model. The purposes of this study are to identify the current process in the production line and to formulate a linear programming model that would suggest a viable product mix to ensure optimum profitability for the company. ABC Sdn Bhd is selected as a case study company for product mix profit maximization study. Some conclusive observations have been drawn and recommendations have been suggested. This study will provide the company and other companies, particularly in Malaysia, an exposure of linear programming method in making decisions to determine the maximum profit for different product mix.

A Linear Programming Model to Evaluate Gas Availability for Vital Industries in Saudi Arabia

1992 ◽  
Vol 43 (11) ◽  
pp. 1035-1045
Author(s):  
S O Duffuaa ◽  
J A Al-Zayer ◽  
M A Al-Marhoun ◽  
M A Al-Saleh
Keyword(s):  
Saudi Arabia ◽  
Linear Programming ◽  
Programming Model ◽  
Linear Programming Model

scholarly journals Wind Farm Cable Connection Layout Optimization with Several Substations

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3615
Author(s):  
Adelaide Cerveira ◽  
Eduardo J. Solteiro Pires ◽  
José Baptista
Keyword(s):  
Energy Production ◽  
Wind Farm ◽  
Programming Model ◽  
Optimal Solution ◽  
Wind Farms ◽  
Green Energy ◽  
Fossil Energy ◽  
Proposed Model ◽  
Short Time ◽  
Cable Connection

Green energy has become a media issue due to climate changes, and consequently, the population has become more aware of pollution. Wind farms are an essential energy production alternative to fossil energy. The incentive to produce wind energy was a government policy some decades ago to decrease carbon emissions. In recent decades, wind farms were formed by a substation and a couple of turbines. Nowadays, wind farms are designed with hundreds of turbines requiring more than one substation. This paper formulates an integer linear programming model to design wind farms’ cable layout with several turbines. The proposed model obtains the optimal solution considering different cable types, infrastructure costs, and energy losses. An additional constraint was considered to limit the number of cables that cross a walkway, i.e., the number of connections between a set of wind turbines and the remaining wind farm. Furthermore, considering a discrete set of possible turbine locations, the model allows identifying those that should be present in the optimal solution, thereby addressing the optimal location of the substation(s) in the wind farm. The paper illustrates solutions and the associated costs of two wind farms, with up to 102 turbines and three substations in the optimal solution, selected among sixteen possible places. The optimal solutions are obtained in a short time.

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