Search

Your search keyword '"Czarnigowska, Agata"' showing total 2 results
Start Over Author "Czarnigowska, Agata" Topic mixed integer linear programming
2 results on '"Czarnigowska, Agata"'

1. Decision model for planning material supply channels in construction.

Author

Jaśkowski, Piotr, Sobotka, Anna, and Czarnigowska, Agata

Subjects
*CONSTRUCTION materials, *DECISION making, *CONSTRUCTION projects, *MIXED integer linear programming, *INVENTORY control, *ECONOMICS
Abstract

Material supply-related decisions strongly affect economic performance of construction projects. To facilitate planning, the authors put forward a mixed integer linear programming model for optimizing supplies of materials or components that are consumed irregularly. The model's objective function is minimizing the total inventory management cost. As material prices change over time and cannot be predicted with certainty, they are expressed as fuzzy values with triangular membership functions. The planning horizon is divided into units of time to allow for seasonal changes and scope variations that affect consumption of materials. The model enables the user to determine economic order quantities for consecutive periods of construction works and to select most economical supply channels of a particular material/component. The model allows for material/component substitution. Substitutes may differ in level of prefabrication and thus in costs of on-site processing. To solve the problem the fuzzy model is converted into a three-objective linear program with crisp coefficients. An example illustrates benefits of using the proposed approach in reducing the total inventory cost. [ABSTRACT FROM AUTHOR]

Published
2018
Full Text
View/download PDF

2. SELECTING MATERIAL SUPPLY CHANNELS FOR CONSTRUCTION PROJECTS: A DECISION MODEL.

Author

Jaśkowski, Piotr, Sobotka, Anna, and Czarnigowska, Agata

Subjects
*SUPPLY chains, *CONSTRUCTION projects, *DECISION making, *LINEAR programming, *INVENTORY control
Abstract

The purpose of research is to analyse and model the construction project's material supply to support logistic decisions. Materials management and delivery planning decisions have a considerable impact on economic outcomes of projects: they condition the flow of works and strongly affect cost. With regard to cost, the factors to be considered are not only the delivery quantities and time, but also selection of suppliers, places of depot, or the level of pre-processing, prefabrication or assembly prior to delivery. To allow for specific conditions of construction operations, the problem was approached by defining the decision problem, constructing the model and finally applying the model to find solutions of a notional case. The proposed model is a mixed integer linear programming model for optimizing supplies with materials consumed irregularly, enabling the user to determine economic order quantities for consecutive periods of construction works and to choose from available supply channels of a particular material/component or its substitutes, if applicable. The model enables the user to minimize total inventory management cost including costs of on-site pre-processing. It can be the basis of decision support tools. Though the paper presents a construction-customized model of supplies with only one type of material, it can be easily adapted to planning any other materials or components that require pre-processing prior to their application, with this pre-processing possible to be conducted on- or off-site. [ABSTRACT FROM AUTHOR]

Published
2014

Catalog

Books, media, physical & digital resources
See catalog results