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Sławomir Biruk
Faculty of Civil Engineering and Architecture, Lublin University of Technology, 40 Nadbystrzycka St., 20-618 Lublin, Poland

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Journal article
Published: 21 May 2021 in Sustainability
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Reducing the duration of construction works requires additional organizational measures, such as selecting construction methods that assure a shorter realization time, engaging additional resources, working overtime, or allowing construction works to be performed simultaneously in the same working units. The simultaneous work of crews may affect the quality of works and the efficiency of construction processes. This article presents a simulation model aimed at assessing the impact of the overlap period on the extension of the working time of the crews and the reduction of a repetitive project’s duration in random conditions. The purpose of simulation studies is to provide construction managers with guidelines when deciding on the dates of starting the sequential technological process lines realized by specialized working crews, for sustainable scheduling and organization of construction projects.

ACS Style

Sławomir Biruk; Łukasz Rzepecki. A Simulation Model of Construction Projects Executed in Random Conditions with the Overlapping Construction Works. Sustainability 2021, 13, 5795 .

AMA Style

Sławomir Biruk, Łukasz Rzepecki. A Simulation Model of Construction Projects Executed in Random Conditions with the Overlapping Construction Works. Sustainability. 2021; 13 (11):5795.

Chicago/Turabian Style

Sławomir Biruk; Łukasz Rzepecki. 2021. "A Simulation Model of Construction Projects Executed in Random Conditions with the Overlapping Construction Works." Sustainability 13, no. 11: 5795.

Journal article
Published: 12 November 2020 in Applied Sciences
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Both the construction clients and the contractors want their projects delivered on time. Construction schedules, usually tight from the beginning, tend to expire as the progress of works is disturbed by materializing risks. As consequence, the project’s original milestones are delayed. To protect the due date and, at the same time, avoid changes to the logic of work, the manager needs to the project progress and, if delays occur, speed up processes not yet completed. The authors investigate the problem of selecting the optimal set of actions of responding to schedule delays. They put forward a simulation-based method of selecting schedule compression measures (speeding up processes) and determining the best moment to take such actions. The idea is explained using a simple case. The results confirm that it is possible to find an easily implementable schedule crashing mode to answer schedule disturbances. The proposed method enables minimizing the cost of schedule crashing actions and the cost of delays as well as increasing the robustness of the schedule by reducing differences between the actual and the as-planned process starts. It is intended as a decision support tool to help construction managers prepare better reactive schedules. The lowest costs are achieved if the acceleration measures are implemented with some time lag to the occurrence of delays.

ACS Style

Sławomir Biruk; Piotr Jaśkowski. Selection of the Optimal Actions for Crashing Processes Duration to Increase the Robustness of Construction Schedules. Applied Sciences 2020, 10, 8028 .

AMA Style

Sławomir Biruk, Piotr Jaśkowski. Selection of the Optimal Actions for Crashing Processes Duration to Increase the Robustness of Construction Schedules. Applied Sciences. 2020; 10 (22):8028.

Chicago/Turabian Style

Sławomir Biruk; Piotr Jaśkowski. 2020. "Selection of the Optimal Actions for Crashing Processes Duration to Increase the Robustness of Construction Schedules." Applied Sciences 10, no. 22: 8028.

Journal article
Published: 08 June 2020 in JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT
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The highest degree of construction works harmonization can be achieved when planning a repetitive project with processes replicated many times in work zones of identical size. In practice, structural considerations affect the way of dividing the object under construction into zones differing in terms of scope and quantity of works. Due to this fact, individual processes are being allotted to different non-identical zones. Most methods intended for scheduling repetitive processes were developed with the assumption that the work zones are identical and that a particular process cannot be concurrently conducted. To address this gap, the authors put forward a mathematical model of the problem of scheduling of repetitive processes that are repeated in different work zones with the following assumption: several crews of the same type are available, thus particular process can run simultaneously in different locations. The aim of optimization is minimizing the idle time of all crews under the constraint of not exceeding the contractual project duration. The proposed mixed binary linear programming model can be solved using software available in the market or developed into a dedicated system to support decisions. To illustrate the benefits of the model, an example of scheduling interior finishing works was provided.

ACS Style

Piotr Jaskowski; Slawomir Biruk. SCHEDULING OF REPETITIVE CONSTRUCTION PROCESSES WITH CONCURRENT WORK OF SIMILARLY SPECIALIZED CREWS. JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 2020, 26, 579 -589.

AMA Style

Piotr Jaskowski, Slawomir Biruk. SCHEDULING OF REPETITIVE CONSTRUCTION PROCESSES WITH CONCURRENT WORK OF SIMILARLY SPECIALIZED CREWS. JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT. 2020; 26 (6):579-589.

Chicago/Turabian Style

Piotr Jaskowski; Slawomir Biruk. 2020. "SCHEDULING OF REPETITIVE CONSTRUCTION PROCESSES WITH CONCURRENT WORK OF SIMILARLY SPECIALIZED CREWS." JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 26, no. 6: 579-589.

Journal article
Published: 01 December 2019 in Archives of Civil Engineering
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Most construction projects involve subcontracting some work packages. A subcontractor is employed on the basis of their bid as well as according to their availability. A viable schedule must account for resource availability constraints. These resources (e.g. crews, subcontractors) engage in many projects, so they become at the disposal for a new project only in certain periods. One of the key tasks of a planner is thus synchronizing the work of resources between concurrent projects. The paper presents a mathematical model of the problem of selecting subcontractors or general contractor’s crews for a time-constrained project that accounts for the availability of contractors, as well as for the cost of subcontracting works. The proposed mixed integer-binary linear programming model enables the user to perform the time/cost trade-off analysis.

ACS Style

S. Biruk; P. Jaskowski; M. Krzemiński. Model of Construction Subcontractors Selection with Time Windows for their Availability. Archives of Civil Engineering 2019, 65, 295 -307.

AMA Style

S. Biruk, P. Jaskowski, M. Krzemiński. Model of Construction Subcontractors Selection with Time Windows for their Availability. Archives of Civil Engineering. 2019; 65 (4):295-307.

Chicago/Turabian Style

S. Biruk; P. Jaskowski; M. Krzemiński. 2019. "Model of Construction Subcontractors Selection with Time Windows for their Availability." Archives of Civil Engineering 65, no. 4: 295-307.

Conference paper
Published: 18 September 2019 in IOP Conference Series: Materials Science and Engineering
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The selection of suppliers is one of the key issues of supply logistics of any business entity. Due to the globalization of the economy and the rapid technological progress, the choice of products and the number of vendors is growing, which makes the selection process difficult. The specific character of the construction projects (one-off contracts with no incentives of the steady orders from one client, the need to adjust the batch size to the pace of the construction works whereas this pace is affected by risks and uncertainties, short time for planning, etc.) poses extra challenges to the suppliers' production and transportation capacities and defines what "capable suppliers" mean for the project success. Therefore, the criteria of a construction project supplier selection go far beyond the obvious "price". They need to refer to the supplier's bid as well as the supplier's own qualities (financial standing, reputation, flexibility). Though the selection process is expected to be based on unequivocal and objective input, in practice, it rests upon opinions and artificial measures used in lieu of the complete information. This input is, thus, fuzzy by nature and ignoring this fact may lead to wrong decisions. Therefore, the authors analyze the ways of quantifying supplier selection criteria and the methods of using them in the decision-making process presented in the literature. Then, they present a numerical example of supplier selection based on AHP with the fuzzy input, juxtaposing it with the results of the "classical" AHP with a crisp input. The results are different. Though this difference cannot be generalized, it indicates that the method of analysis may strongly affect the decision-makers choices.

ACS Style

Sławomir Biruk; Piotr Jaskowski; Agata Czarnigowska. Fuzzy AHP for selecting suppliers of construction materials. IOP Conference Series: Materials Science and Engineering 2019, 603, 032093 .

AMA Style

Sławomir Biruk, Piotr Jaskowski, Agata Czarnigowska. Fuzzy AHP for selecting suppliers of construction materials. IOP Conference Series: Materials Science and Engineering. 2019; 603 (3):032093.

Chicago/Turabian Style

Sławomir Biruk; Piotr Jaskowski; Agata Czarnigowska. 2019. "Fuzzy AHP for selecting suppliers of construction materials." IOP Conference Series: Materials Science and Engineering 603, no. 3: 032093.

Conference paper
Published: 18 September 2019 in IOP Conference Series: Materials Science and Engineering
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The Monte Carlo simulation has become a standard tool in the practice of planning risk-affected projects. In particular, it is frequently applied to testing the impact of risk on schedule networks with deterministic structures and random activity durations defined by distribution functions of any type. The accuracy of simulation-based estimates can be improved by increasing the number of replications or by applying variance reduction methods. This paper focuses on the latter and analyzes the impact of the variance reduction method on the scale of the standard error of the estimated mean value of project duration. Three methods of variance reduction were examined: the Quasi-Monte Carlo with Weyl sequence sampling, the antithetic variates, and the Latin Hypercube Sampling. The object of the simulation experiment was a sample network model with the activity durations of triangular distributions. This type of distribution was selected as it is often applied in the practice of construction scheduling to capture the variability of operating conditions in the absence of grounds for assuming other types of distribution. The results of the sample simulation provided an indirect proof that applying variance reduction measures may reduce the time of the simulation experiment (reduced number of replications) as well as improve the confidence in the estimates of the model's characteristics.

ACS Style

Slawomir Biruk; Piotr Jaskowski; Agata Czarnigowska. Assessing the Efficiency of Variance Reduction Methods in the Construction Project Network Simulation. IOP Conference Series: Materials Science and Engineering 2019, 603, 032094 .

AMA Style

Slawomir Biruk, Piotr Jaskowski, Agata Czarnigowska. Assessing the Efficiency of Variance Reduction Methods in the Construction Project Network Simulation. IOP Conference Series: Materials Science and Engineering. 2019; 603 (3):032094.

Chicago/Turabian Style

Slawomir Biruk; Piotr Jaskowski; Agata Czarnigowska. 2019. "Assessing the Efficiency of Variance Reduction Methods in the Construction Project Network Simulation." IOP Conference Series: Materials Science and Engineering 603, no. 3: 032094.

Journal article
Published: 06 March 2019 in Computation
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This study adopts the flow shop concept used in industrial production to schedule repetitive non-linear construction projects, where specialized groups of workers execute processes in work zones (buildings) in a predefined order common to all groups. This problem is characteristic of construction projects that involve erecting multiple buildings. As the duration of the project heavily depends upon the sequence of the work zones, this study aims at providing a model and a practical approach for finding the optimal solution that assures the shortest duration of the project, allows the contractor to complete particular work zones (buildings) as soon as possible (without idle time), and conforms to a predefined sequence of work zone completion. This last constraint may arise from the client’s requirements or physical conditions of the project and has not been addressed by existing scheduling methods. Reducing the duration of the entire project brings the benefit of lower indirect costs and, if accompanied by a reduced duration of completing particular buildings (i.e., work zones), may also provide the opportunity to sell project deliverables sooner, thus improving the economic efficiency of the project. In search of optimal schedules, the authors apply the algorithms of Minimum Hamiltonian Cycle/Asymmetric Traveling Salesman Problem (ATSP).

ACS Style

Piotr Jaśkowski; Sławomir Biruk. Minimizing the Duration of Repetitive Construction Processes with Work Continuity Constraints. Computation 2019, 7, 14 .

AMA Style

Piotr Jaśkowski, Sławomir Biruk. Minimizing the Duration of Repetitive Construction Processes with Work Continuity Constraints. Computation. 2019; 7 (1):14.

Chicago/Turabian Style

Piotr Jaśkowski; Sławomir Biruk. 2019. "Minimizing the Duration of Repetitive Construction Processes with Work Continuity Constraints." Computation 7, no. 1: 14.

Conference paper
Published: 24 February 2019 in IOP Conference Series: Materials Science and Engineering
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One of the main factors having a decisive impact on the completion date of a construction project and its total cost is the duration of individual processes. Projects such as the construction of multi-storey residential and public buildings, line facilities, highways, networks of external installations or pipelines are conducted with time-location methods of work organization. It is possible to notice the cyclical nature of building processes in projects, whose characteristic parameter is length or height. In such cases, works are entrusted to specialized organizational units (crews, teams) that conduct repeated operations on identical or similar sections, called units. With each repetition of the operations, workers acquire more and more practical experience which has a positive effect on their work efficiency and leads to a reduction in the time and cost of a construction project. The learning theory bring on a mathematical description of the interdependence between the repetitions number of the same task and work efficiency. Taking into account the learning effect allows for a more accurate estimation of the individual construction processes duration, which may provide an advantage at the stage of submitting bids in tenders. The aim of research is to prepare the implementation plan of repetitive construction processes conducted in a multi-storey residential building. The schedule will take into account the impact of the learning and forgetting effect for the duration of construction works and the interruptions in crews work on the example of finishing works. Due to the lack of commercial software for preparing construction schedules taking into account the learning and forgetting impact, a spreadsheet was developed in MS Excel to set the start and end dates and time buffers of construction processes.

ACS Style

Sławomir Biruk; Lukasz Rzepecki. Scheduling Repetitive Construction Processes Using the Learning-Forgetting Theory. IOP Conference Series: Materials Science and Engineering 2019, 471, 112039 .

AMA Style

Sławomir Biruk, Lukasz Rzepecki. Scheduling Repetitive Construction Processes Using the Learning-Forgetting Theory. IOP Conference Series: Materials Science and Engineering. 2019; 471 (11):112039.

Chicago/Turabian Style

Sławomir Biruk; Lukasz Rzepecki. 2019. "Scheduling Repetitive Construction Processes Using the Learning-Forgetting Theory." IOP Conference Series: Materials Science and Engineering 471, no. 11: 112039.

Conference paper
Published: 23 February 2019 in IOP Conference Series: Materials Science and Engineering
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A competitive tender with the lowest price as the only (or the main) criterion of contractor selection is one of the most common approaches to procurement in construction. On the one hand, it is expected to offer the greatest benefits of competition to the client; on the other hand, it forces numerous competitors to engage time and resources for bid preparation with a low chance to win the job. To stay in the market, the contractor needs to foresee the behaviour of the competitors (which implies knowing who they are and what prices are they likely to offer), and apply some strategy to increase his/her probability to win without compromising the profits. A number of mathematical models of competitive bidding process can be found in the literature, from the earliest basing on probability theory, to more recent that apply artificial neural networks or fuzzy set theory. The paper presents a probability-based method of estimating the optimal bid price (which means a price of maximum expected value of the contractor's profit) in lowest bid tenders that stems from Friedman's model (1956). The authors discuss the assumptions that make the model applicable to real-life situations of specialized construction contractors. A worked example based on case-study data is presented to illustrate the idea. To be used in practice, the proposed model has to be fed with up-to-date results of tenders (number of competitors, and their bid prices). The proposed strategy thus rests upon careful monitoring of the market and internal condition of the bidder.

ACS Style

Piotr Jaskowski; Sławomir Biruk; Agata Czarnigowska. Strategy for Mark-up Definition in Competitive Tenders for Construction Work. IOP Conference Series: Materials Science and Engineering 2019, 471, 112060 .

AMA Style

Piotr Jaskowski, Sławomir Biruk, Agata Czarnigowska. Strategy for Mark-up Definition in Competitive Tenders for Construction Work. IOP Conference Series: Materials Science and Engineering. 2019; 471 (11):112060.

Chicago/Turabian Style

Piotr Jaskowski; Sławomir Biruk; Agata Czarnigowska. 2019. "Strategy for Mark-up Definition in Competitive Tenders for Construction Work." IOP Conference Series: Materials Science and Engineering 471, no. 11: 112060.

Conference paper
Published: 23 February 2019 in IOP Conference Series: Materials Science and Engineering
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The continuous growth of competition on the construction market results in the fact that construction companies are forced to keep searching for solutions facilitating the building process and construction logistics. In the recent decades, one of the most fascinating ideas which enable a real improvement in the aspect of a company's competitiveness on the market is supply chain management. It has undergone a transformation from fragmented actions to integrated operations intending to optimize the flow of physical resources and information. The first step towards the application of the modern logistics tools is the selection and evaluation of entities involved in a cooperation within the supply chain framework. The selection of reliable partners to supply a construction site or a building company may reduce the operational costs, minimize inventory and improve timeliness as well as the quality of offered services. Any mistakes made in the process of supplier selection may lead to issues such as supply delays, difficulties in keeping contract deadlines and even complete failure of a project or bankruptcy of a construction company. An 18th century criterion for the selection of the most preferable candidate developed by Nicolas de Condorcet is commonly accepted owing to its fair rules of choice (anyone who defeats most of their competitors in a direct confrontation wins). Due to its democratic approach, most criteria decide as to the selection of the winner. Should the choice of a winner or establishing a Condorcet ranking from the perspective of the social choice theory prove impossible, the selected candidate ought to be as much similar to a winner in the Condorcet sense as possible. The theory was developed in order to facilitate the selection of the most suitable candidate in the election, however it may also find application in the selection of a supply chain elements evaluated with the use of multiple criteria. There are a number of decision-making methods which fulfil the Condorcet criterion. They vary in their computational complexity and may provide different final order. The intention of this paper is to review the methods which may offer support while selecting the most preferable supplier of construction products.

ACS Style

Michal Tomczak; Sławomir Biruk; Piotr Jaskowski. Selection of Construction Products Suppliers According to the Condorcet Criterion. IOP Conference Series: Materials Science and Engineering 2019, 471, 112068 .

AMA Style

Michal Tomczak, Sławomir Biruk, Piotr Jaskowski. Selection of Construction Products Suppliers According to the Condorcet Criterion. IOP Conference Series: Materials Science and Engineering. 2019; 471 (11):112068.

Chicago/Turabian Style

Michal Tomczak; Sławomir Biruk; Piotr Jaskowski. 2019. "Selection of Construction Products Suppliers According to the Condorcet Criterion." IOP Conference Series: Materials Science and Engineering 471, no. 11: 112068.

Journal article
Published: 20 November 2018 in Open Engineering
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The basic operation of a construction company involves the execution of tasks (building structures or building works) on sites. These projects are linked by the common resources of a building company used for the execution of different orders. The scheduling of a construction company programme is a continuous process with a dynamically changing look-ahead and scope of works. Decisions made on site by junior managers are based on their experience and intuition and are attempts at purposeful regulation – adaptation of the operative plan to the directive schedule, agreed with the investor, considering the progress of work. The quality of management decisions can be improved by implementing computer-based decision-supporting systems.

ACS Style

Sławomir Biruk. A computer-based renewable resource management system for a construction company. Open Engineering 2018, 8, 440 -446.

AMA Style

Sławomir Biruk. A computer-based renewable resource management system for a construction company. Open Engineering. 2018; 8 (1):440-446.

Chicago/Turabian Style

Sławomir Biruk. 2018. "A computer-based renewable resource management system for a construction company." Open Engineering 8, no. 1: 440-446.

Conference paper
Published: 29 October 2018 in MATEC Web of Conferences
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Linear projects such as highways, multi-storey buildings or pipelines are implemented by repeating the sequences of processes on units. Repetitive operations affect acquiring more and more experience, which shortens the duration of subsequent activities. On the other hand, the possible breaks in work make this effect disappear. Breaks at work are most often caused by the lack of crew work continuity. While delaying the subsequent sequences of processes properly, it is possible to reduce interruptions and limit the forgetting effect. A simulation method for scheduling linear construction projects has been developed, taking into account the learning and forgetting effect. It allows to increase the probability of the crew work continuity while meeting the project deadline with a specific probability. As a result, the estimation of the project duration is more accurate, which may provide an advantage at the stage of submitting offers in tenders for construction works.

ACS Style

Łukasz Rzepecki; Sławomir Biruk. Simulation Method for Scheduling Linear Construction Projects Using the Learning– Forgetting Effect. MATEC Web of Conferences 2018, 219, 04007 .

AMA Style

Łukasz Rzepecki, Sławomir Biruk. Simulation Method for Scheduling Linear Construction Projects Using the Learning– Forgetting Effect. MATEC Web of Conferences. 2018; 219 ():04007.

Chicago/Turabian Style

Łukasz Rzepecki; Sławomir Biruk. 2018. "Simulation Method for Scheduling Linear Construction Projects Using the Learning– Forgetting Effect." MATEC Web of Conferences 219, no. : 04007.

Journal article
Published: 29 June 2018 in JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT
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Renewable resource levelling is the core of the scheduling process. A perfect schedule ensures that resource supply corresponds to the demand at every unit of project time. A classic approach to resource levelling in schedules with predefined project completion dates consists in manipulating processes start dates. Resource deployment can be also improved by considering alternative construction processes execution modes with various crew formations, and by allowing activities to be split. There are other possibilities: in many practical cases, the activities’ precedence logic predefined in the network model can be changed with no harm to the project outcome. Within the structure of the project network model, some precedence relations between activities would definitely be of fixed (hard) character, whereas some might allow the activities to be executed at the same time or arranged in a variety of logical sequences. The authors use soft precedence relations that let the processes run in reversed order or that can be cancelled, in search for improved resource usage profiles. The benefits of scheduling with soft precedence relations are demonstrated by an example.

ACS Style

Piotr Jaskowski; Slawomir Biruk. REDUCING RENEWABLE RESOURCE DEMAND FLUCTUATION USING SOFT PRECEDENCE RELATIONS IN PROJECT SCHEDULING. JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 2018, 24, 355 -363.

AMA Style

Piotr Jaskowski, Slawomir Biruk. REDUCING RENEWABLE RESOURCE DEMAND FLUCTUATION USING SOFT PRECEDENCE RELATIONS IN PROJECT SCHEDULING. JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT. 2018; 24 (4):355-363.

Chicago/Turabian Style

Piotr Jaskowski; Slawomir Biruk. 2018. "REDUCING RENEWABLE RESOURCE DEMAND FLUCTUATION USING SOFT PRECEDENCE RELATIONS IN PROJECT SCHEDULING." JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 24, no. 4: 355-363.

Conference paper
Published: 01 October 2017 in IOP Conference Series: Materials Science and Engineering
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Subcontracting has been a worldwide practice in the construction industry. It enables the construction enterprises to focus on their core competences and, at the same time, it makes complex project possible to be delivered. Since general contractors bear full responsibility for the works carried out by their subcontractors, it is their task and their risk to select a right subcontractor for a particular work. Although subcontractor management has been admitted to significantly affect the construction project's performance, current practices and past research deal with subcontractor management and scheduling separately. The proposed model aims to support subcontracting decisions by integrating subcontractor selection with scheduling to enable the general contractor to select the optimal combination of subcontractors and own crews for all work packages of the project. The model allows for the interactions between the subcontractors and their impacts on the overall project performance in terms of cost and, indirectly, time and quality. The model is intended to be used at the general contractor's bid preparation stage. The authors claim that the subcontracting decisions should be taken in a two-stage process. The first stage is a prequalification – provision of a short list of capable and reliable subcontractors; this stage is not the focus of the paper. The resulting pool of available resources is divided into two subsets: subcontractors, and general contractor's in-house crews. Once it has been defined, the next stage is to assign them to the work packages that, bound by fixed precedence constraints, form the project's network diagram. Each package is possible to be delivered by the general contractor's crew or some of the potential subcontractors, at a specific time and cost. Particular crews and subcontractors can be contracted more than one package, but not at the same time. Other constraints include the predefined project completion date (the project is not allowed to take longer) and maximum total value of subcontracted work. The problem is modelled as a mixed binary linear program that minimizes project cost. It can be solved using universal solvers (e.g. LINGO, AIMMS, CPLEX, MATLAB and Optimization Toolbox, etc.). However, developing a dedicated decision-support tool would facilitate practical applications. To illustrate the idea of the model, the authors present a numerical example to find the optimal set of resources allocated to a project.

ACS Style

Sławomir Biruk; Piotr Jaśkowski; Agata Czarnigowska. Minimizing Project Cost by Integrating Subcontractor Selection Decisions with Scheduling. IOP Conference Series: Materials Science and Engineering 2017, 245, 72007 .

AMA Style

Sławomir Biruk, Piotr Jaśkowski, Agata Czarnigowska. Minimizing Project Cost by Integrating Subcontractor Selection Decisions with Scheduling. IOP Conference Series: Materials Science and Engineering. 2017; 245 (7):72007.

Chicago/Turabian Style

Sławomir Biruk; Piotr Jaśkowski; Agata Czarnigowska. 2017. "Minimizing Project Cost by Integrating Subcontractor Selection Decisions with Scheduling." IOP Conference Series: Materials Science and Engineering 245, no. 7: 72007.

Conference paper
Published: 01 October 2017 in IOP Conference Series: Materials Science and Engineering
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Many civil engineering projects involve sets of tasks repeated in a predefined sequence in a number of work areas along a particular route. A useful graphical representation of schedules of such projects is time-distance diagrams that clearly show what process is conducted at a particular point of time and in particular location. With repetitive tasks, the quality of project performance is conditioned by the ability of the planner to optimize workflow by synchronizing the works and resources, which usually means that resources are planned to be continuously utilized. However, construction processes are prone to risks, and a fully synchronized schedule may expire if a disturbance (bad weather, machine failure etc.) affects even one task. In such cases, works need to be rescheduled, and another optimal schedule should be built for the changed circumstances. This typically means that, to meet the fixed completion date, durations of operations have to be reduced. A number of measures are possible to achieve such reduction: working overtime, employing more resources or relocating resources from less to more critical tasks, but they all come at a considerable cost and affect the whole project. The paper investigates the problem of selecting the measures that reduce durations of tasks of a linear project so that the cost of these measures is kept to the minimum and proposes an algorithm that could be applied to find optimal solutions as the need to reschedule arises. Considering that civil engineering projects, such as road building, usually involve less process types than construction projects, the complexity of scheduling problems is lower, and precise optimization algorithms can be applied. Therefore, the authors put forward a linear programming model of the problem and illustrate its principle of operation with an example.

ACS Style

Sławomir Biruk; Piotr Jaśkowski; Agata Czarnigowska. Updating Linear Schedules with Lowest Cost: a Linear Programming Model. IOP Conference Series: Materials Science and Engineering 2017, 245, 72011 .

AMA Style

Sławomir Biruk, Piotr Jaśkowski, Agata Czarnigowska. Updating Linear Schedules with Lowest Cost: a Linear Programming Model. IOP Conference Series: Materials Science and Engineering. 2017; 245 ():72011.

Chicago/Turabian Style

Sławomir Biruk; Piotr Jaśkowski; Agata Czarnigowska. 2017. "Updating Linear Schedules with Lowest Cost: a Linear Programming Model." IOP Conference Series: Materials Science and Engineering 245, no. : 72011.

Journal article
Published: 23 May 2017 in Przegląd Naukowy Inżynieria i Kształtowanie Środowiska
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Construction projects encompass repetitive works carried out on the same or similar object parts, called working units. Due to the cyclical nature of construction processes it is possible to use the learning-forgetting theory to construction projects scheduling. The article shows an example of using learning-forgetting theory in the planning of implementation multi-storey residential building in random conditions.

ACS Style

Sławomir Biruk; Łukasz Rzepecki. Wpływ zjawiska uczenia i zapominania na czas realizacji powtarzalnych procesów budowlanych realizowanych w warunkach losowych. Przegląd Naukowy Inżynieria i Kształtowanie Środowiska 2017, 26, 202 -209.

AMA Style

Sławomir Biruk, Łukasz Rzepecki. Wpływ zjawiska uczenia i zapominania na czas realizacji powtarzalnych procesów budowlanych realizowanych w warunkach losowych. Przegląd Naukowy Inżynieria i Kształtowanie Środowiska. 2017; 26 (2):202-209.

Chicago/Turabian Style

Sławomir Biruk; Łukasz Rzepecki. 2017. "Wpływ zjawiska uczenia i zapominania na czas realizacji powtarzalnych procesów budowlanych realizowanych w warunkach losowych." Przegląd Naukowy Inżynieria i Kształtowanie Środowiska 26, no. 2: 202-209.

Journal article
Published: 28 March 2017 in Archives of Civil Engineering
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Production rates for various activities and overall construction project duration are significantly influenced by crew formation. Crews are composed of available renewable resources. Construction companies tend to reduce the number of permanent employees, which reduces fixed costs, but at the same time limits production capacity. Therefore, construction project planning must be carried out by means of scheduling methods which allow for resource constrains. Authors create a mathematical model for optimized scheduling of linear construction projects with consideration of resources and work continuity constraints. Proposed approach enables user to select optimal crew formation under limited resource supply. This minimizes project duration and improves renewable resource utilization in construction linear projects. This paper presents mixed integer linear programming to model this problem and uses a case study to illustrate it.

ACS Style

S. Biruk; P. Jaśkowski. Scheduling Linear Construction Projects with Constraints on Resource Availability. Archives of Civil Engineering 2017, 63, 3 -15.

AMA Style

S. Biruk, P. Jaśkowski. Scheduling Linear Construction Projects with Constraints on Resource Availability. Archives of Civil Engineering. 2017; 63 (1):3-15.

Chicago/Turabian Style

S. Biruk; P. Jaśkowski. 2017. "Scheduling Linear Construction Projects with Constraints on Resource Availability." Archives of Civil Engineering 63, no. 1: 3-15.

Journal article
Published: 01 March 2017 in Engineering Management in Production and Services
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The authors aim to provide a set of tools to facilitate the main stages of the competitive bidding process for construction contractors. These involve 1) deciding whether to bid, 2) calculating the total price, and 3) breaking down the total price into the items of the bill of quantities or the schedule of payments to optimise contractor cash flows. To define factors that affect the decision to bid, the authors rely upon literature on the subject and put forward that multi-criteria methods are applied to calculate a single measure of contract attractiveness (utility value). An attractive contract implies that the contractor is likely to offer a lower price to increase chances of winning the competition. The total bid price is thus to be interpolated between the lowest acceptable and the highest justifiable price based on the contract attractiveness. With the total bid price established, the next step is to split it between the items of the schedule of payments. A linear programming model is proposed for this purpose. The application of the models is illustrated with a numerical example.The model produces an economically justified bid price together with its breakdown, maintaining the logical proportion between unit prices of particular items of the schedule of payment. Contrary to most methods presented in the literature, the method does not focus on the trade-off between probability of winning and the price but is solely devoted to defining the most reasonable price under project-specific circumstances.The approach proposed in the paper promotes a systematic approach to real-life bidding problems. It integrates practices observed in operation of construction enterprises and uses directly available input. It may facilitate establishing the contractor’s in-house procedures and managerial decision support systems for the pricing process.

ACS Style

Sławomir Biruk; Piotr Jaśkowski; Agata Czarnigowska. Modelling contractor’s bidding decision. Engineering Management in Production and Services 2017, 9, 64 -73.

AMA Style

Sławomir Biruk, Piotr Jaśkowski, Agata Czarnigowska. Modelling contractor’s bidding decision. Engineering Management in Production and Services. 2017; 9 (1):64-73.

Chicago/Turabian Style

Sławomir Biruk; Piotr Jaśkowski; Agata Czarnigowska. 2017. "Modelling contractor’s bidding decision." Engineering Management in Production and Services 9, no. 1: 64-73.

Journal article
Published: 01 January 2017 in Procedia Engineering
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ACS Style

Sławomir Biruk; Piotr Jaśkowski; Agata Czarnigowska. Modeling Contractor's Bidding Decisions. Procedia Engineering 2017, 182, 91 -98.

AMA Style

Sławomir Biruk, Piotr Jaśkowski, Agata Czarnigowska. Modeling Contractor's Bidding Decisions. Procedia Engineering. 2017; 182 ():91-98.

Chicago/Turabian Style

Sławomir Biruk; Piotr Jaśkowski; Agata Czarnigowska. 2017. "Modeling Contractor's Bidding Decisions." Procedia Engineering 182, no. : 91-98.

Research paper
Published: 12 October 2016 in International Journal of Civil Engineering
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A formwork is a structure used to contain poured concrete and to mold it to the required dimensions. Different formwork systems provide a wide range of concrete construction solutions that can be chosen to suit the needs of a particular structure. The selection of panels and the design of the formwork layout for concrete structures, especially if the panels are to be reused many times to form different work zones, are one of the most complex tasks in formwork construction. It influences the quality of work, construction time, site safety and cost. The formwork costs account for a significant part of the total costs for concrete works. The problem of the selection and layout of reusable panel forms is solved mainly based on the intuitive judgment of experienced engineers in collaboration with the form system supplier. This study proposes a mixed integer linear programming modeling approach to support the formwork planning process. The problem consists in determining the number and sizes of the panels according to the geometry of the concrete elements to minimize the rental cost of wall shuttering in a building divided into work zones that are to be completed in sequence, reusing the chosen panels. The model can be solved using typical software dedicated to mixed integer linear programs. A simple example is used to illustrate the efficiency of the proposed approach, where the formwork rental cost is 7.31 % lower than the rental costs of panels and corners optimized without consideration of the reuse in consecutive zones.

ACS Style

Slawomir Biruk; Piotr Jaskowski. Optimization of Vertical Formwork Layout Plans Using Mixed Integer Linear Programming. International Journal of Civil Engineering 2016, 15, 125 -133.

AMA Style

Slawomir Biruk, Piotr Jaskowski. Optimization of Vertical Formwork Layout Plans Using Mixed Integer Linear Programming. International Journal of Civil Engineering. 2016; 15 (2):125-133.

Chicago/Turabian Style

Slawomir Biruk; Piotr Jaskowski. 2016. "Optimization of Vertical Formwork Layout Plans Using Mixed Integer Linear Programming." International Journal of Civil Engineering 15, no. 2: 125-133.