Anna Sobotka

Multi‐attribute analysis for the eco‐energetic assessment of the building life cycle

Abstract In the recent years, attention has been attracted to the development of activities (developing and implementation of standards, directives, regulations, policies etc.) related to the environmental protection and implementation of the principles of sustainable development. Also in Poland, principles ofthat concept are put into practice. There is, however, a shortage of elaborations which the future investor or designer could, in an easy way, utilise for the selection of environment‐friendly materials, technologies, building utilities and so forth, i.e. to design a facility which causes the least harm possible to the environment, maintaining at the same time low energy demand during its life cycle. According to the philosophy of environmental protection, a building design should take into consideration its entire life cycle, and its structure and utilities should allow the supplies of energy needed for heating to be eliminated while using the building. The present paper aims to give multi‐attribute...

Multicriteria construction project scheduling method using evolutionary algorithm

The project owners demand that construction projects are to be accomplished on time and to budget. Regardless of the construction project procurement system, duration and cost are the key factors determining project’s economic efficiency and fulfillment of the owner’s needs and requirements. Beside quality, they are basic criteria taken into account in project planning, scheduling and contractors selection. The multicriteria optimization of schedules is a complex question being among NP-hard problems. There is a demand for methods of proved reliability that would facilitate solving practical cases within relatively short time and allow for numerous constraints typical for construction. Due to limitations of precise methods in solving complex practical issues and imperfection of heuristic methods, the metaheuristic approach (evolutionary algorithm) has been adopted to solve multiple-objective combinatorial optimization scheduling problems. The method has been applied to solve a practical case of bicriteria (time and cost minimization) scheduling optimization and contractor selection problem.

Using soft precedence relations for reduction of the construction project duration

Abstract Current network techniques used for project scheduling presume that there is only one logical sequence of activities. However, in reality, the precedence logic of activities is not necessarily unchangeable. There are two types of relations between activities: fixed (hard) and soft. Current scheduling methods do not differentiate between these two types of relations and require a planner to choose one particular logical sequence based on some assumptions. The paper presents a model that allows for “weakening” the links between activities, i.e. that permits concurrent execution of activities or reversing their order, but this may require additional resource-consuming works or expenditures. The model involves two subtypes of soft logic: REVERSED and CANCELED to represent the soft relations between activities. Its mathematical form is a mixed linear integer programming model of minimizing the project duration without exceeding the allowed budget. The paper presents an example of practical application...

Decision-making model for choosing residential building repair variants

AbstractDuring the use of buildings it becomes necessary to carry out repair works including modernisation. Deciding on the choice of repair solutions is a difficult and complex task. Building administrators have to consider both, the benefits of some repair works, and limitations due to the availability of funds. Selection of a repair solution, bearing in mind the above, requires a comprehensive approach that will allow assessment of the building condition and determining the repair scope required. The research conducted by the authors was aimed at developing a decision-making model and its computer-aided implementation, taking into account a number of operating demands. The system algorithm proposed comprises five stages including: building condition assessment, building use value evaluation, repair classification, multiple variants of repair and the choice of repair solutions. The article describes individual stages of the model in detail, giving numerical application examples of the method for repair ...

Analysis of logistics for construction site supply with reinforcing steel

Owing to the numerous advantages of this technology, the continuous development of monolithic constructions have been made possible. The complexity of structures using this technology have been made possible thanks to the use of modern shuttering, the production of high quality concrete mixes carried out by professional concrete-mixing plants and efficient logistics supporting investment projects. The weakest element in organisation of these works is the supply of reinforcing steel, an expensive resource which is consumed in large quantities thus requiring extensive logistical planning. On the basis of their professional experience, the authors of this paper present their analysis of logistical models for supplying construction sites with reinforcing steel. Using the AHP method, they carry out a multi criteria evaluation of possible supply systems. Then, applying decision inventory theory models, they determine control quantities leading to logistic system optimisation according to the selected criteria.