11 research outputs found
Deadline and Budget Overruns of Construction Projects – Multiple Case-Study
Građevinski projekt je nerutinski, neponovljivi i jedinstveni pothvat koji ima zasebne vremenske, financijske i tehničke izvedbene ciljeve. Upravljati građevinskim projektom znači primijeniti znanja, vještine i tehnike radi regulacije tijeka projektnih aktivnosti kako bi se ostvarili ciljevi projekta. To primarno znači završetak unutar ugovorenog roka i proračuna projekta, uz zadovoljavajuću kvalitetu izvedbe. Problem prekoračenja ugovorenog roka i proračuna globalna je pojava, kako u razvijenim, tako i u zemljama u razvoju. Stoga je i često u središtu istraživačkog interesa s različitih aspekata promatranja. Pritom se koriste razne istraživačke metode i matematički alati obrade podataka. Cilj ovog rada je prepoznati veličine i uzroke prekoračenja u projektima te dati smjernice za njihovo smanjenje. U svrhu istraživanja korištena je „multiple case-study“, tj. studija više slučajeva. Prikupljeni su podaci za dvanaest različitih projekata koji su se izvodili na području Republike Hrvatske u 2018. godini. Podaci uključuju tehničke karakteristike objekata, ugovorene rokove i troškove, kvalitetu izvedbe, veličine prekoračenja te uzroke njihovog nastanka. Podaci su prikupljeni uvidom u dokumentaciju te intervjuiranjem voditelja svakog pojedinog gradilišta. Analizom i obradom podataka prepoznati su trendovi prekoračenja, kao i slabe točke u planiranju i vođenju navedenih projekata, na temelju čega su dane smjernice i preporuke u svrhu smanjenja prekoračenja rokova i troškova u budućim projektima.A construction project is non-routine, unrepeatable and a unique venture that has separate time, financial and technical achievement goals. Managing a construction project means applying knowledge, skills, and techniques to regulate the course of project activities to achieve project goals. Primarily, this means construction completion within the project contracted deadline and the budget, with satisfactory performance quality. The problem of overruns on the agreed deadline and budget is a global phenomenon, both in developed and developing countries and is therefore often at the center of research interest from various observation aspects. In doing so, various research methods and mathematical data processing tools are used. The aim of this paper is to identify the proportion and causes of overruns in projects and to provide guidelines for their reduction. For the purpose of the research, a multiple case study was used. Data for twelve different projects that were carried out in the Republic of Croatia in 2018 were collected. Data includes technical characteristics of objects, contracted deadlines and costs, performance quality, overrun proportion, and causes of their occurrence. The data were collected by inspecting the documentation and interviewing the manager of each construction site. By data analysis and processing, trends of overruns are identified as well as weak points in planning and managing these project. On that basis, guidelines and recommendations are given to reduce the time and costs overruns in future projects
ELEMENTARY SCHOOL BUILDINGS CONDITION ASSESSMENT: CASE OF PRIMORJE-GORSKI KOTAR COUNTY (CROATIA)
This study deals with the condition examination of elementary school buildings in Primorje-Gorski Kotar County, Croatia. For schools to be functional and of high quality, adequate maintenance is mandatory. Therefore, school maintenance programs need information on the building\u27s condition based on systematic and comprehensive assessments as a primary input. This study aims to establish a framework for assessing the condition of school buildings, based on which information can be obtained quickly and practically regarding the condition of all critical facility elements. To this end, a database on schools and their conditions was created. The conditions of school buildings in terms of damage and defects and their causes were determined. Descriptive and inferential statistical operations were performed on the collected data. A condition assessment of the buildings was performed using a questionnaire survey among the principals, based on the school buildings division model developed in this study; the model presents building elements and a systematic visual condition rating scale. According to the available data, this is Croatia\u27s first condition assessment on elementary school buildings. The main results show that on average, the examined schools are in good condition. Moreover, according to the results, the school building condition is most affected by dilapidation and lack of financial resources
Quality Cost Analysis of Selected Construction Works
Rad se bavi problematikom troškova kvalitete građevinskih radova. Ovaj se problem, osobito kod nas, do sada nije istraživao u značajnijoj mjeri. U današnje vrijeme, kvaliteta zauzima značajno mjesto u svim djelatnostima pa tako i građevinskoj. Poznato je da zadovoljenje tražene kvalitete predstavlja i jedno od bitnih mjerila uspješnosti realizacije građevinskih projekata. Naravno da postizanje kvalitete iziskuje i trošenje financijskih sredstava. Međutim, uobičajeno je da su ti troškovi sadržani u ukupnim troškovima te se njihovoj kvantifikaciji ne posvećuje posebna pažnja. Za očekivati je da će daljnjim porastom složenosti građevinskih projekata i povećanjem zahtjeva kvalitete problem kvantifikacije ovih troškova dobivati na važnosti. Kao doprinos rješavanju ovog problema provedeno je istraživanje prikupljanjem i analizom podataka o troškovima kvalitete putem anketnog upitnika među zaposlenicima građevinskih tvrtki. Istraživanjem se pokušalo utvrditi uvjetuju li trajanje i troškovi rada i materijala građevinske radne operacije iznos troškova kvalitete. Kriteriji za odabir građevinskih radova bili su učestalost pojavljivanja u projektima visokogradnje te broj radnih operacija od kojih se sastoje. Odabrano je pet radova (izrada oplate temelja, armiranje šipkastom armaturom, ugrađivanje betona C16/20, zidanje zidova opekom, žbukanje zidova), svaki sastavljen od najmanje tri radne operacije. Odabranim radovima određeni su postotni udjeli troškova kvalitete po radnim operacijama, koji su zatim uspoređeni s udjelima vremena i troškova rada i materijala. Vremenski i troškovni udjeli izračunati su pomoću normativa građevinskih radova, dok su udjeli troškova kvalitete procijenjeni na temelju podataka dobivenih anketiranjem. Rezultati su pokazali da iznos troškova kvalitete radnih operacija ispitivanih radova nije nužno proporcionalan trajanju i troškovima rada i materijala. Drugim riječima, mjerilo postignute kvalitete nije samo vrijeme rada uloženo u njeno dostizanje, kao ni kvaliteta ugrađenih materijala, već i kvaliteta samog rada izvršitelja. Pored toga, kad se radnoj operaciji pristupa s potrebnom pozornošću, smanjuje se i mogućnost pogreške, potreban dodatni rad, a time i dodatni troškovi za kvalitetu.The paper deals with the issue of the quality cost of construction works. This problem, especially in our country, has not significantly been explored. At present, quality plays an important role in all activities, including construction. It is well known that meeting the required quality is also one of the essential benchmarks of a successful realization of construction projects. Of course, achieving quality requires spending financial resources. However, it is common that these costs are included in total costs. Thus, not enough attention is paid to their quantification. It is expected that the problem of quantification of these costs will gain more importance with further growth of construction project complexity and quality requirements. As a contribution to solving this problem, a research was conducted through a survey among the employees of construction companies by collecting data on quality costs. The research attempted to determine whether the quality cost depend on time and costs of labor and materials of construction work operation. Criteria for the selection of construction works were the frequency of appearances in building projects and the number of work operations they consisted of. Five works were selected (making formwork for foundation, reinforcing with steel rods, concreting C16/20, wall masonry, plastering of walls), each consisting of at least three work operations. Percentage shares of quality costs are determined in selected works and then compared with shares of time and costs of labor and materials. Time and cost percentage shares were calculated using the norms of construction works while the shares of the quality cost were estimated based on the data obtained by the survey. The results have shown that the amount of quality cost in construction work is not necessarily proportional to the time and cost of the work operation. In other words, the measure of the achieved quality is not merely the time of work invested in its achievement, as well as quality of embedded materials, but the quality of the work of the contractor. Additionally, when a work operation is approached with necessary care, the possibility of error, additional work, and therefore additional quality costs are also reduced
TIME DEVIATION ANALYSIS OF THE BASELINE PLAN ON THE CASE STUDY: IMPLEMENTATION OF REINFORCED CONCRETE WORKS ON A SCHOOL CONSTRUCTION PROJECT IN THE REPUBLIC OF CROATIA
In the paper, an analysis of the time aspect of the baseline plan for the execution of reinforced concrete works was carried out on a case study. The case study covers the construction of a public school in the Republic of Croatia, which was completed in 2023. By analyzing the baseline plan, it was determined that it has shortcomings and that the duration of the activities does not correlate with those actually achieved. Compared to the initial 86 working days, the baseline plan actually lasted 272 working days, which is an overrun of 216.28%. The leading causes of overruns in individual activities were identified, and lack of communication between project participants proved to be one of the particularly frequent ones. Recommendations were given for better time planning and for reducing deviations from planned durations, which can improve the processes of time management and project management in general
CONNECTING DURATION AND ACTIVITY COSTS IN CONSTRUCTION PROJECT
U radu su teorijski obrađeni troškovi u građevinskim projektima, S-krivulja koja povezuje troškove i trajanje u projektu, te je detaljno opisana stara toplana grada Osijeka (Munjara) koja se planira prenamjeniti u tehnički muzej.
U praktičnom dijelu se pristupilo planiranju projekta prenamjene te je prikazana strukturna raščlamba projekta (WBS), dinamički plan (gantogram), troškovnik radova s analizom cijena, histogram troškova, Pareto dijagram, te na kraju i način povezivanja troškova i vremena u projektu (S-krivulja).In this work are theoretically covered expenses from civil engineering projects, Scurve that connects expenses with duration in a project and it is described, in detail, an old heating plant of Osijek (Munjara) which is planned to be converted into tech museum.
In practical segment it has been approached towards planning a project convertion and it is shown structural breakdown of the project (WBS), dynamic plan (gantogram), bill of quantites with unit cost estimate, histogram of expenses, Pareto diagram and in the end the way of connecting durations and activity costs inside project (S-curve)
Development of the model for efficient maintenance management of public educational buildings
U doktorskoj disertaciji je provedeno istraživanje o upravljanju održavanjem u javnim osnovnim i srednjim školama s područja Primorsko-goranske županije sa svrhom doprinosa teoriji o održavanju školskih građevina, otkrivanju problema koji na spomenute građevine utječu te formuliranju kriterija najbolje prakse za njihovo održavanje. Metodama anketiranja ravnatelja škola te studijom više slučajeva u kojoj su detaljno analizirani podaci dobiveni od osnivača škola, utvrđene su brojne neadekvatnosti u trenutnom upravljačkom procesu. Predlaže se razvoj modela koji bi pridonio učinkovitijem upravljanju održavanjem škola kojim će se postići proaktivno i kvalitetno održavanje, smanjenje potrošnje resursa za održavanje, minimiziranje zastoja te povećanje zadovoljstva korisnika, tj. zaposlenika i učenika. Model upravljanja održavanjem u ovom radu predstavlja grafički i opisni alat koji usmjerava voditelje školskih ustanova i druge dionike kako se provodi učinkovito upravljanje aktivnostima održavanja. Za razvoj modela su uz podatke dobivene anketiranjem ravnatelja i studijom više slučajeva korišteni i podaci dobiveni anketiranjem građevinskih eksperata i korisnika škola što daje sveobuhvatan model temeljen na inputima svih važnih sudionika u procesu održavanja školskih građevina; građevinskih eksperata, osnivača, ravnatelja te zaposlenika i učenika škola. Razvijeni model uključuje procesni dijagram te opise i smjernice za izvršavanje pojedinih čimbenika unutar funkcija upravljanja koje uključuju planiranje održavanja, organiziranje održavanja, vođenje održavanja i kontroliranje održavanja. Model također sadrži sustav prioriteta radova održavanja temeljen na mišljenju eksperata, zaposlenika i učenika škola, a razvijen koristeći metodu ponderiranog zbroja; matematički model procjene troškova održavanja temeljen na regresijskoj analizi; i sustav pokazatelja izvršenja za ocjenu uspješnosti cjelokupnog procesa upravljanja održavanjem. Implementiranjem ovakvog modela u rad škola očekuje se poboljšati trenutne procese upravljanja održavanjem, prvenstveno u smislu učinkovitijeg trošenja sredstava za održavanje gdje su trenutno prepoznate značajne neadekvatnosti.In this doctoral dissertation, research on maintenance management in public primary and secondary schools in the Primorje-Gorski Kotar County was conducted to contribute to the theory of maintenance of school buildings, discover problems that affect these buildings and formulate the best practice criteria for their maintenance. Numerous inadequacies in the current management process were identified by methods of surveying school principals and a multiple case study in which the data obtained from school founders were analysed in detail. It is proposed to develop a model that would contribute to more efficient management of schools maintenance, which will achieve proactively and quality maintenance, reduce maintenance resource consumption, minimize downtime and increase customer satisfaction, i.e. staff and students. The maintenance management model in this work is a graphical and descriptive tool that guides school leaders and other stakeholders on how to effectively manage maintenance activities. For the model development, in addition to the data obtained by surveying principals and case studies, data obtained by surveying construction experts and school's users were used, which provides a comprehensive model based on inputs of all important participants in the maintenance of school buildings; construction experts, founders, principals, employees and students. The developed model includes a process diagram, descriptions and guidelines for implementation of individual factors within management functions that include maintenance planning, maintenance organization, maintenance directing, and maintenance control. The model also includes a maintenance prioritization system based on the opinions of experts, staff, and students, developed using the weighted sum method; a mathematical model for predicting maintenance costs based on regression analysis; and a system of performance indicators to assess the performance of the entire maintenance management process. It is expected that the implementation of this model in schools will improve the current processes of maintenance management, especially in terms of a more efficient use of funds for maintenance, where significant shortcomings are currently identified
AUSWIRKUNGEN DER ART DER FINANZIERUNG AUF DIE KOSTEN-ZEIT-ASPEKTE OFFENTLICHER UND SOZIALER BAUTEN
U radu je prikazana usporedba tradicionalnog (proračunskog) modela nabave javnih i
društvenih građevina s modelom javno-privatnog partnerstva (neproračunski model).
Istraživanjem kojim je obuhvaćeno devet izgrađenih građevina s područja Republike
Hrvatske, usporedno su analizirane javne i društvene građevine isporučene tradicionalno
i po modelu JPP-a. Rezultati pokazuju veću efikasnost JPP modela u izgradnji javnih i
društvenih građevina unutar planiranog proračuna i roka građenja.The comparison of the traditional (budget-funded) public building procurement model
with the public private partnership (non-budget funded) model is presented in the paper.
Public service buildings procured based on the traditional model and those procured
according to the PPP model are compared in the scope of research involving nine buildings
realized in the Republic of Croatia. The results point to greater efficiency of the PPP
model in the construction of public service buildings, with regard to both cost and time
of construction work.In der Abhandlung wird der Vergleich des traditionellen (Haushalts-)Modells der
Beschaffung öffentlicher und sozialer Bauten mit dem Modell der öffentlich-privaten
Partnerschaft (Nicht-Haushalts-Modell) dargelegt. Bei der Untersuchung, mit welcher
neun errichtete Gebäude auf dem Gebiet der Republik Kroatien umfasst wurden, wurden
parallel öffentliche und soziale Bauten, die auf traditionelle und nach dem ÖPP-Modell
ausgeliefert wurden, analysiert. Die Ergebnisse zeigen eine höhere Effizienz bei den
ÖPP-Modellen beim Bau öffentlicher und sozialer Gebäude innerhalb des geplanten
Haushalts und der Baufrist
Analysis of the Current Maintenance Management Process in School Buildings: Study Area of Primorje-Gorski Kotar County, Republic of Croatia
Due to their educational purpose, impact on users and quality of education, school buildings are vital institutions in the community, and their adequate maintenance should be mandatory. Studies conducted around the world point to specific inadequacies that occur in the school maintenance segment, however studies that examine the entire maintenance management process in detail are rare. With such studies, it is possible to observe all components of maintenance and its management in the observed buildings, it is possible to get a detailed insight into the present inadequacies and problems, and give the best possible answer to them. Observing the territory of the Republic of Croatia, it was noticed that there are no adequate databases on school building maintenance. Given all the above, this paper aims to establish a methodological framework and analyze the entire maintenance management process in Croatian schools to detect potential inadequacies, reveal problems, and identify areas for action to improve maintenance performance and carry out maintenance more efficiently. The current maintenance management process of elementary school buildings in the Primorje-Gorski Kotar County, Republic of Croatia, was examined based on the developed methodological framework. Data on the management process were collected through a questionnaire survey among school principals. The questionnaire was compiled based on an extensive literature review. Maintenance performance through management functions was investigated, namely: maintenance planning, maintenance organization, maintenance directing, and maintenance controlling. Important management factors within each of the mentioned functions were observed. The data analysis revealed specific inadequacies and problems in the maintenance process, and it was shown that maintenance management is not entirely effective. Recommendations were given to improve the current situation. In this way, it is possible to quickly and easily examine the entire management process and identify measures that need to be introduced in schools to improve their business in the maintenance segment. The developed methodological framework can be applied to schools from other areas as well as to other types of buildings
Group decision-making in civil engineering based on AHP and PROMETHEE methods
The Analytical Hierarchy Process (AHP) and PROMETHEE have gained increasing attention in the field of construction management as techniques for the analysis of complex situations and as decision support for decision makers. However, these two methods in themselves or their potential applications to problems of construction management are not sufficiently defined in the existing literature. The environment of group decision-making bring even more challenges. This paper consolidates and critically discusses the current knowledge on the application of AHP and PROMETHEE methods in the light of the specifics of the construction industry. A systematic literature review was used to select the contributions indexed in the databases Scopus and Web of Science. The findings indicate that the studies deal with broad topics and different aspects in different phases of civil engineering projects. This paper provides a useful reference work for researchers and practitioners interested in the application of AHP and PROMEETHEE as tools for group decision-making in civil engineering
Predicting buildings construction cost overruns on the basis of cost overruns structure
In construction practice, contractually agreed costs are often exceeded, which interferes with the sustainable realization of construction projects. The research described in this paper covers 24 new construction, renovation and reconstruction projects in the Republic of Croatia realized in the years 2006 to 2017, in order to analyse the occurrence of cost overruns more precisely with regard to the source of the overruns. It was found that additional work is the main source of cost overruns: firstly, additional work as a result of the client’s change orders and then unforeseen construction work as a result of unforeseen circumstances. As for the additional works, they are carried out at the client’s request and are not necessary for the safety and stability of the building. Using linear regression and “soft computing” methods, the possibility of modelling the relationship between contractually agreed and realized construction costs with satisfactory accuracy was tested. The model with the values of the natural logarithms of the variables, modelled according to the time–cost model of Bromilow, proved to be of the highest accuracy