This paper presents an analysis of selected criteria for choosing the most suitable contractor in a public
procurement process, and for appointing the contractor whose tender best meets the criteria used in Poland, Germany, United Kingdom and France. The national procurement regulations are based on the European directive 2004/18/EC that allows for an objective multi-criteria assessment of a tender offer. As foreign examples prove, the procedures used in the process of tenders’ evaluation, followed by a selection of the best bidder, vary, depending on the country of their application. Moreover, they show that the lowest price is not the most appropriate choice for the contracting authorities, if they adhere to the rule ‘value for money’.

This paper describes the problem of project maturity for construction companies when analyzed by their ability to execute construction investment projects. On the basis of survey results it was revealed that the success of a company is connected with the increasing level of project maturity as a condition for a successful project management.

This paper presents options for implementing an advisory system to support production processes in the
construction sector. With case-based reasoning methods (implementation of learning from examples) and simulation, an advisory system can be built on the foundation of a knowledge base, being a systematic collection of information aimed at the advancement of construction processes on site. Based on the evaluation of studied process results acquired in specified conditions (using the abductive approach), options are proposed for new case design engineering. The paper presents an example of application of case-based reasoning in delivering ready-mixed concrete to a large construction site from two batching plants.

One of the most difficult problems in construction having to take an objective decision,
especially when selecting contractors. The decision making process is both complicated and
time consuming (due to the complex nature of construction projects). Many experts, with
extensive knowledge of the Construction Industry, take subjective decisions, related to verbal
methods of decision making. The previously mentioned difficulties mainly relate to the creation
of a relevant criteria set, answering the decision makers questions. A proper criteria set and
mathematical tools (like computer calculation algorithms with multi-criteria analysis) could
significantly improve objective decision making. The authors present a case study – selection
of contractors – with detailed calculations of AHP method.

When planning a construction investment, an evaluation is often performed. In order to make the best possible choice, it is necessary to define the correct specification of the evaluation criteria which will guide us through the decision-supporting procedure. Some criteria refer to measurable phenomena, hence they can easily be defined. Others, however, need to be described with linguistic methods and require adequate scale and identification methods. This article presents methods used to prepare and choose the correct criteria for carrying out an assessment of the building investment, applicable to various criteria and different multi-criteria methods.

In the world of literature, only a few methods for assessing partner relationships in construction project have been described. This paper analyses five of them. Methodology is discussed as well as the advantages and disadvantages of each individual method. On this basis, the guidelines for the development of a comprehensive system of assessment and control of partner relationships have been summarised.

The paper presents the idea of flexible design in the construction sector. Guidelines of the evaluation of a road infrastructure were discussed based on JASPERS Blue Book. An idea of how to proceed is presented through infrastructure projects concerned with economic efficiency analysis using a flexible approach. Moreover, the issue of flexibility is presented using the POZNAN BY-PASS A2 as the example of infrastructure, to which efficiency analysis was applied to variant solutions.

The considerable degree of complexity found in construction work, as well as project susceptibility to unpredictable conditions determines the need of ongoing progress monitoring and continuous time-cost analysis during the execution of work. Financial and material analysis, using the Earned Value method applied to the construction of an Underground Gas Storage Facility, including project risks which occurred during the project, helped to identify the advantages and limitations in application of this method of monitoring work progress.

This paper describes the legal conditions for the award of Green Public Procurement for construction works. Environmental criteria that can be used in contracts for construction works are also presented. The author presents current practice in green procurement organized by Polish authorities.

The certification of green buildings has become more and more popular as a tool used for comparison and evaluation of newly built structures. The authors of this article analyse various certification systems of green buildings in Poland with particular interest paid to newly built multi- and one-family residential buildings. The reason there is such little interest in green building certification processes is also considered. Additionally, the major constraints behind introducing green building certificates for newly built structures is also presented. The Article also presents an analysis of benefits resulting from green building certification for investors, contractors and final users of a particular building.

The paper presents a case study of an innovative method of porous pavement rehabilitation works. The innovation consists in applying an additional piece of plant to collect the supplied asphalt-aggregate mix and feed it pavers. Observations and measurements of construction process output collected during an A73 highway rehabilitation project in the Netherlands can be used for creation of asphalt-aggregate mix supply models and comparing efficiency of using certain plant sets.

The paper discusses an assessment of the technical condition of the historic Palace Complex in Gorzanow, and the reasons behind the damage incurred to its structure. The research has been carried out by the authors. The article presents the scope of implemented repair work intended to secure the building against further degradation, as well as a work plan that would make it possible to fully reconstruct the most valuable qualities of the palace in Gorzanow. The primary focus of the article has been applied to technical and organisational issues, regarding an ambitious endeavour to restore the building in question to full functionality and serviceability.

A gravel piles foundation technique as an alternative to the soil replacement method is presented in this paper. The authors describe both technologies and carry on the comparative analysis, regarding the economical and technical aspects of them. The work is based on a real life example from multi-storey car park construction project carried out in Tychy.

The paper discusses the process of restoration of the outer courtyard on Wawel Hill, which was part of a project co-funded by the European Union under the “Infrastructure and Environment” programme. The location and specificity of the restoration works generated many technological and organisational problems during their implementation (most of which could not have been predicted earlier), which in turn determined the different approaches and concepts available for solving them. The article is therefore a kind of case study, which demonstrates the specific implementation al problems associated with this project, as well as identifying the mistakes to be avoided, on one hand, as well as to point to concepts which are worth repeating.

The paper looks at the systematic approach to management throughout the entire project life cycle. Some significant activities within particular phases of the overall process have been described in order to point out the fundamentals for a successful project. Planning assumptions, predicted risks and resources are always the basic parameters necessary for the optimal establishment of projec objectives. Further stages of projects need to be driven through those objectives while all contemporary constraints in the execution of the project have to be overcome by project team. The monitoring of progress and costs will always be critical for each contractor, however it becomes a real challenge when project requires the demanding quality and safety arrangements, as is the case when constructing nuclear power plants. The highest standards and procedures recommended for project management have been established in the UK and the USA. The main conclusions concerning the most important stages of project have been supported by examples of construction processes experienced by author in those countries.

Technical maintenance of existing buildings will be an important issue in the near future. The purpose of the research presented in this paper was to identify element deterioration in the course of maintaining residential apartments. In order to reach the research goal, the author analysed symptoms of the technical wear increase, i.e. performing the identification of mechanisms responsible the defect formation. The scope of this work required the creation of an original qualitative model for pinpointing defects and transferring this information into a quantitative one. Thus, it was possible to analyse the reason-effect phenomena ‘defect – technical wear’ relevant to the most important elements make an assessment of such an apartment block. The building in question is a block of apartment houses in Wrocław. The information gathered should prove indispensable for housing management and other such organisations involved with technical building services, as it can serve to influence the maintenance quality level of different types of existing buildings.

This article presents the technological issues of carrying out repair works on a pithead building in Upper Silesia. The problems diagnosed by the authors and connected with the uncontrolled settling of the pithead building and neighbouring facilities caused the need for developing a repair works schedule that enabled its continuous operation. The paper also presents a method for the implementation of the recommended works and their impact on the technical condition of this object, its functionality and operation.

The main goal of monitoring construction projects is to identify any negative deviations from the approved plan. Therefore, the possibility of the permanently monitoring the progress of construction work scope is an extremely important issue. The authors’ main goal is to present a method of graphical visualization which can be used for tracking progress in relation to the time, progress as a supplement of the cyclograms.

The paper discusses the functions and objectives of systems, used for a building’s monitoring process, through the subsequent stages of a building’s service life. The authors present the result of research regarding the monitoring of two buildings undergoing refurbishment: an industrial hall and a multi-storey general use building. Refurbishment of the industrial building included upgrading an existing production line, associated with an increased technological load. In the general-use building the foundations were strengthened in connection with the construction of a new multi-storey building in the immediate vicinity. The process of reinforcing footings, or – pilings – was monitored, as well as the preservation of an existing building, during the course of the construction of the new building.

This paper is a collection of solutions, which when used in construction would allow for improvements in living conditions and reduce costs, while adhering to regulatory and consumer requirements. The proposals presented apply to single-family houses, tall buildings, but also entire urban agglomerations. There is also a multitude of solutions resulting from the revitalization of urban areas. All of the above is presented in terms of new technologies which support zero-energy and environmentally friendly construction.

The paper presents a method of network planning CPM – Critical Path Method. The author compares models of optimal solutions to design deadlines for individual works, taking various leading technical resources such as is labor and a tower crane into account.

This paper presents a concise review of some methods and techniques that are used for assessing how long construction works (namely – activities or work tasks in terms of programming) will take. As background for the discussion, some definitions are given and preliminary remarks are made. Chosen methods and techniques for the assessing of construction works duration are presented and briefly discussed. Additionally, some results from the author’s initial research on the construction works duration are presented.

The paper presents a selected proposal of establishing labour input in concreting jobs carried out in difficult atmospheric conditions. The author aims to answer the following question: is there a common-sense limit, e.g. defined by temperature, to which concreting works can be performed safely and efficiently and beyond which it is more reasonable to stop the work and wait for more favourable weather conditions.

This paper concerns an integrated construction planning method which combines both BIM and location-based management and scheduling techniques. The methodology of 5D planning and LB(M)S is explained using appropriate examples. Location-based scheduling and management is an entirely new production system for construction. It uses locations as the container of project data as well as flow-line scheduling. The author believes it can be a powerful tool for schedule optimization, but still needs investigation regarding the scope of quantity takeoff methods and further improvements of a self-learning labor-demand data base.

This paper presents uses for the KASS (Krzeminski Algorithm Scheduling System) program in scheduling for construction projects. The program serves as a tool for scheduling for up to a maximum of 10 work crews at 13 work sites, and then applies a complete overhaul in simulation. This paper describes the first version of the program released in 2012, as well as the modified version introduced in 2013.

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.

Production downtime results from the technological regime of production processes, established in production diagrams as network nodes. Their direct cause in the lack of harmonization between working teams, diversity of performance of hardware units – working in mixed systems, and different labor construction processes, performed on the same working plots. Time and costs analysis lies in optimizing the downtime of production resources using the “by-pass” production, which allows production labor (R) and hardware measures (S) for the implementation of part of the process. This tool is defined in network nodes, slowing down the production and binding the run of the production front with a two criteria network plan: technologically and organizationally. The technique is based on an algorithm of the limitations of renewable resources of means of production, which assumes the full availability of construction materials, available from storage sites. The paper presents an analysis of fixed and variable investments costs in terms of compensating for downtime.

The assignment problem consists of allocating renewable resources (construction equipment, crews, or contractors) of limited availability to a set of activities. The classical model for this problem minimizes the total time or cost of completing all activities with the assumption that each activity is assigned to one particular resource. This paper systematizes and describes extensions of these assumptions, considering the effects of task sequence: parallel, serial and hybrid (modeled by means of network methods). This study proposes algorithms for the solution of presented models, which can be used in construction project scheduling.

This paper presents the elements, the goals and the functions as well as the rules for the elaboration of a property management plan. The authors analyzed its importance in the decisionmaking process (the immediate and long-term decisions) concerning property management. Particular attention has been paid to the multifaceted character of this problem. 

W artykule przedstawiono elementy, cele i funkcje oraz zasady opracowania prawidłowego planu zarządzania nieruchomością. Przeanalizowano jego znaczenie w procesie podejmowania decyzji doraźnych i długoterminowych dotyczących zarządzania nieruchomością. Zwrócono uwagę na  wielopłaszczyznowy charakter tego zagadnienia. 

Planning the course of construction works is complex and complicated, requiring reflection on many aspects related to the implementation of the project. High importance is placed on duration and cost of the project, as well as the separation of necessary resources. This article deals with the subject of planning the size of the workforce for a project, presenting widely available workforce planning methods, in accordance with academic approaches. A survey was conducted among Polish construction contractors – with differing scopes and ranges of activities, regarding practical methods for determining the size of the workforce. Factors that influence the size of a construction team were also investigated. The results obtained will develop with further research in this area. 

Planowanie przebiegu robót budowlanych jest zadaniem złożonym i skomplikowanym, wymagającym zastanowienia się nad wieloma aspektami związanymi z realizacją inwestycji budowlanej. Jednym z nich, mającym duże znaczenie dla czasu i kosztów przedsięwzięcia, jest rozdzielenie niezbędnych  zasobów. W artykule podjęto temat planowania poziomu zatrudnienia dla realizacji robót budowlanych i przedstawiono ogólnodostępne metody planowania zatrudnienia, zgodne z podejściem akademickim. Przeprowadzono ankietę wśród polskich wykonawców budowlanych – o różnym zakresie i zasięgu działalności, na temat praktycznego sposobu ustalania wielkości zatrudnienia. Badano również czynniki, które wpływają na liczebność brygad roboczych. Otrzymane wyniki zostaną rozwinięte o dalsze badania w tym zakresie. 

On the basis of traditional methods for the technical normalization of working time, this present paper presents the use of probabilistic models of working processes for use when estimating the execution time for selected building processes.

SZACOWANIE CZASU REALIZACJI PROCESÓW BUDOWLANYCH Z WYKORZYSTANIEM MODELI PROBABILISTYCZNYCH

Na bazie tradycyjnych metod normowania technicznego czasu pracy w artykule przedstawiono wykorzystanie probabilistycznych modeli procesów budowlanych w zagadnieniu szacowania czasu realizacji wybranych procesów budowlanych. 

Construction schedule optimization generally deals with the identification of the feasible sequence of activities and allocation of modes that provide the most efficient construction performance according to the assumed evaluation criteria. The specific technological order of activities results in the numerous feasible sequences of activities and availability of alternative modes results in the numerous mode combinations. Construction scheduling becomes, therefore, a difficult combinatorial  problem that is usually underestimated by the planners. This is the main reason for obtaining schedules that result in construction implementation lasting too long and costing too much. It is, nevertheless, possible to identify the construction schedules that provide excellent results. A simple, simulationbased approach is presented in this paper. Its originality results from nature of applied  model and a way the calculations are made. The effectiveness of the approach is illustrated by means of a sample analysis based on data provided by [1]. The approach also proved useful for solving scheduling problems in engineering practice.

HARMONOGRAMOWANIE PRZEDSIĘWZIĘCIA JAKO ZAGADNIENIE KOMBINATORYCZNE 

Optymalizacja harmonogramu przedsięwzięcia polega na doborze takiej dopuszczalnej kolejności wykonywania prac oraz przydzieleniu takich sposobów wykonania operacjom, które zapewnią najlepsze możliwe, zgodnie z przyjętymi kryteriami oceny harmonogramu, wykonanie przedsięwzięcia. Z technologicznego porządku prac wynika zwykle duża, a często nawet astronomiczna liczba ich dopuszczalnych uporządkowań. Złożoność procesu harmonogramowania dodatkowo podwyższa dostępność alternatywnych sposobów wykonania prac. Harmonogramowanie przedsięwzięć stanowi więc w istocie trudne, a przy tym niedoceniane przez planistów, zagadnienie kombinatoryczne. W rezultacie otrzymujemy harmonogramy odpowiadające nadmiernie czaso- i kosztochłonnej realizacji przedsięwzięcia. Przy odrobinie wysiłku można jednak uzyskać harmonogramy, które odpowiadają krótkiej i taniej realizacji przedsięwzięcia. Temu celowi służy również autorskie narzędzie symulacyjne przedstawione w pracy. Stanowi ono oryginalne podejście zarówno w zakresie modelu, jak i sposobu wykonywania obliczeń, do których dane zaczerpnięto z  pracy [1]. Wyniki pracy zostały także zastosowane w praktyce inżynierskiej 

Construction scheduling deals with the decisions which can affect the feasible sequence of construction activities, the selection of alternative execution modes for the activities and the positioning of the construction in time. Effects of these decisions can be evaluated by means of specific schedule evaluation criteria. However, the peculiarity of construction in civil engineering  causes that the real effects of the construction also depend on the influence of the surrounding environment. For example, construction processes are sensitive to adverse weather. Poor weather influences the actual performance of construction activities. The performance of the activities influences the performance of the whole construction project. Thus, the performance of whole construction project is also influenced by bad weather. Considering the influence of adverse weather is therefore indispensable when preparing a reliable construction schedule. Note, that the effects of poor weather on actual construction performance can be limited by the careful choice of the activity sequence, construction time lines, and the execution modes for various activities. The approach is presented, in this paper therefore provides the appropriate sequence of construction activities, related starting date and the allocation of execution modes to the activities in order to make construction schedule less sensitive to inclement weather.

IDENTYFIKACJA HARMONOGRAMU BUDOWLANEGO NIEWRAŻLIWEGO NA POGODĘ

Harmonogramowanie przedsięwzięcia polega na wyborze właściwej kolejności wykonania prac budowlanych, sposobów wykonania poszczególnych prac oraz umiejscowienia realizacji przedsięwzięcia w czasie. Do oceny efektów tych decyzji są wykorzystywane odpowiednie kryteria, np. planowany czas i koszt wykonania przedsięwzięcia. Zauważmy również, że na skutek specyfiki  produkcji budowlanej rzeczywiste rezultaty wykonania przedsięwzięcia zależą od oddziaływania otoczenia. Typowym przykładem niekorzystnego oddziaływania otoczenia są zmienne warunki pogodowe. Wiele rodzajów prac budowlanych (roboty ziemne, betonowe, montażowe itp.) jest wrażliwych na oddziaływanie warunków pogodowych. Niekorzystne warunki wpływają więc na efekty realizacji prac, które wpływają z kolei na rezultaty realizacji całego przedsięwzięcia. Rezultaty te zależą więc również od warunków pogodowych. W trakcie harmonogramowania przedsięwzięcia jest konieczne uwzględnianie niekorzystnego wpływu pogody na efekty realizacji prac i przedsięwzięcia. Zauważmy przy tym, że wpływ niekorzystnej pogody można ograniczać już na etapie harmonogramowania przedsięwzięcia, dobierając właściwą kolejność wykonania prac, odpowiednie sposoby ich wykonania oraz czas rozpoczęcia przedsięwzięcia. W pracy przedstawiono podejście symulacyjne ułatwiające określenie właściwej kolejności realizacji prac i skojarzonej z nią daty rozpoczęcia przedsięwzięcia oraz odpowiedniego przydziału sposobów wykonania operacjom w warunkach niekorzystnego oddziaływania pogody. 

This paper presents development of the earned value concept regarding forecasting project duration time. On the basis of the calculations carried out for an implemented investment project, consisting of development of the sanitary sewage and municipal water supply system, individual methods and their assumptions were presented and discussed.

W artykule przedstawione zostało rozwinięcie wartości wypracowanej w aspekcie prognozowania terminu końcowego realizacji. Na podstawie obliczeń przeprowadzonych dla zrealizowanej inwestycji obejmującej swoim zakresem rozbudowę kanalizacji sanitarnej i wodociągu wiejskiego przedstawione i omówione  zostały poszczególne metody i ich założenia.

This paper analyses the causes and consequences of stoppages due to cuts in the water supply and sewage systems installations. The bases for the article are direct observations conducted on 8 building projects.

WPŁYW PRZERW NA PRODUKTYWNOŚĆ PRACY PRZY BUDOWIE SIECI WODOCIĄGOWYCH I KANALIZACYJNYCH

W artykule przedstawiona została analiza przyczyn i skutków przerw w pracy przy budowie sieci wodociągowych i kanalizacyjnych. Podstawę artykułu stanowią bezpośrednie obserwacje przeprowadzone na 8 obiektach.