Construction time-cost model in Croatia

The paper deals with the applicability of the time-cost model for calculating the sustainable construction time for building projects in Croatia. In this model the time is expressed as a function of money in the project, while the specific constants K and B need to be determined. These constants depend on economic characteristics of the country or a larger area, therefore had to be separately calculated for a region with similar economic characteristics. The modelling of the constants was performed for two groups of building projects - the roads and residential and office multi-storey buildings. The obtained results have been analyzed and compared to the corresponding results from abroad

Development of a Hybrid Agile Management Model in Local Self-Government Units

Local self-government units (LSGUs) often view project management as an accompanying activity not really giving it the appropriate level of importance. Challenges of traditional project management where the projects are segmented into discrete paths each dependent on the completion of the previous phase but without feedback or iteration can be overwhelming in a rigid governmental organizational structures. Such could be avoided by changing the way the projects are managed and/or changing the organizational structure. In both cases agile approach can be helpful. However, a priori implementation can cause more damage than good. It is the thinking behind the Agile principles that would adapt to the needs and particularities of the work environment it is implemented in, especially in light of the variety of activities of government bodies. The proposed model, Hybrid Agile Model, aims at defining a new, flexible, management structure for local self-government units, based on the development of human resources and constant change of culture, never neglecting the regular activities of such bodies, and all while making them more reliable and effective. The model has been described in detail along with the implementation process that has been tested on LSGU City of Poreč

AGILE ORGANIZATIONAL MODEL FOR MANAGING LOCAL GOVERNMENT PROJECTS

Local self-government units often consider project management as an accompanying activity and therefore do not accord it the appropriate level of importance. The term “agile” refers to a series of methods developed for more flexible project management. Thus, the background of an agile concept and its content are presented in this paper. Furthermore, the concept is compared with traditional project management methodologies. However, a priori implementation of agile-based model in an unrealistic solution can cause more damage than good. Hence, this paper proposes an agile-based matrix organizational model that adapts to the needs and particularities of the work environment in which it implemented, especially the various activities of government bodies. The model will define a new and flexible management structure for local self-government units based on the development of human resources, constant change of culture, and regular activities of government bodies, thereby improving their reliability and effectiveness

Construction time overrun as a function of risk factors

U radu je prikazana analiza istraživanja prekoračenja ugovorenog roka građenja zavisno od rizičnih faktora. Osnovni cilj je utvrđivanje što realnijeg modela za brzu procjenu vremena građenja. Na osnovu podataka za ukupno 53 građevine visokogradnje izgrađene u području Federaciji Bosne i Hercegovine uspostavljeni su modeli za dvije skupine zgrada: nova gradnja i rekonstrukcija, koji su primjenjivi u uvjetima kada postoji realna procjena za pojavu i djelovanje rizičnih faktora.The analysis of overrun of contract-based construction times, as triggered by risk factors, is presented in the paper. The principal objective is to determine a model, as realistic as possible, for rapid estimation of construction time. Based on data from the total of 53 building construction projects realized in the Federation of Bosnia & Herzegovina, appropriate models were established for two building types, i.e. new construction and rehabilitation of existing facilities. These models can be applied in situations where the occurrence and activation of risk factors can realistically be expected

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

Models for rapid evaluation of a sustainable construction time

Analizira se razvoj modela za brzu procjenu vremena građenja, te istražuje mogućnost razvoja i primjene izvornog modela pogodnog za primjenu u Hrvatskoj. Prikazane su glavne karakteristike najznačajnijih modela, te njihova usporedna analiza s ocjenom praktične uporabljivosti. Opisani su rezultati istraživanja provedenog u Hrvatskoj tijekom 2003/05., kojima su predloženi izrazi za proračune održivog roka građenja za nekoliko skupina građevina. Dan je primjer iz visokogradnje.Development of models for rapid evaluation of construction time is analyzed, and possibilities are studied for the development and use of the initial model suitable for use in Croatia. Main properties of the most significant models are presented, including comparative analyses and evaluation of practical usability. The authors present results obtained by the study conducted in Croatia in 2003/05, in which expressions are proposed for calculating sustainable construction times for several groups of buildings. An example from the sphere of building construction is given

Prekoračenje ugovorene cijene kao funkcija prekoračenja ugovorenog vremena građenja

By establishing the model for the quick estimation of the construction time in contracted price function and the construction time overrun model in risk factor function, a logical question arises what effect this has on the contracted price when applying such models in practice. This paper analyses the procedure for establishing a model for building construction structures – new construction. This model expresses the contracted price overrun in relation to the construction time overrun caused by risk factors. The model is in the form of exponential equation whose basic advantage is its form of a natural logarithm. The logarithm transformation enables the use of a single linear regression for determining the model parameters. It is appropriate for the early planning stage under the conditions when there is a real possibility of risk factor occurrence. Due to economic differences, its application is recommended for regions where the research was conducted.Uspostavom modela za brzu procjenu vremena građenja u funkciji ugovorene cijene i modela za prekoračenje vremena u funkciji rizičnih faktora, nameće se logično pitanje što se događa s ugovorenom cijenom građenja primjenom tih modela u praksi. U ovom se radu prikazuje metodološki postupak uspostave modela za objekte visokogradnje kojim se iskazuje prekoračenje ugovorene cijene u ovisnosti od prekoračenja vremena građenja uslijed djelovanja rizičnih faktora. Pretpostavljeni model je u formi eksponencijalne jednadžbe, što je i njegova temeljna prednost. Logaritamska transformacija omogućava primjenu jednostruke linearne regresije za određivanje parametara modela. Model je prikladan za ranu fazu planiranja u uvjetima u kojima postoji realna mogućnost pojave rizičnih faktora. Zbog gospodarskih i drugih razlika njegova je primjena ograničena samo na područje istraživanja

Models for rapid evaluation of a sustainable construction time

Analizira se razvoj modela za brzu procjenu vremena građenja, te istražuje mogućnost razvoja i primjene izvornog modela pogodnog za primjenu u Hrvatskoj. Prikazane su glavne karakteristike najznačajnijih modela, te njihova usporedna analiza s ocjenom praktične uporabljivosti. Opisani su rezultati istraživanja provedenog u Hrvatskoj tijekom 2003/05., kojima su predloženi izrazi za proračune održivog roka građenja za nekoliko skupina građevina. Dan je primjer iz visokogradnje.Development of models for rapid evaluation of construction time is analyzed, and possibilities are studied for the development and use of the initial model suitable for use in Croatia. Main properties of the most significant models are presented, including comparative analyses and evaluation of practical usability. The authors present results obtained by the study conducted in Croatia in 2003/05, in which expressions are proposed for calculating sustainable construction times for several groups of buildings. An example from the sphere of building construction is given

Statistical Data Analysis of Weather Conditions Aiming at Determining the Mathematical Expectation of Construction Site Delays in Rijeka Within a Monthly Period

Meteorološki i klimatski uvjeti mogu uvelike utjecati na kontinuirani i zadovoljavajući tijek izvođenja radova na gradilištu. Posebno je važno, ali nedovoljno primijenjeno u praksi, prilikom izrade vremenskog plana i definiranja roka za građenje uzeti u obzir i moguće zastoje pri radu gradilišta zbog nepovoljnih vremenskih uvjeta. Meteorološki i klimatski uvjeti imaju različit utjecaj ovisno o lokaciji gradilišta. Iz tog razloga, kako bi se statistički obradio utjecaj vremenskih neprilika na području grada Rijeke, s pripadajućom umjereno toplom, vlažnom klimom i vrućim ljetima (Cfa - Köppen-ova klasifikacija klime), od Državnog hidrometeorološkog zavoda (DHMZ) zatraženi su meteorološki podaci o vremenskim neprilikama za vremensko razdoblje od 25 godina, izmjerenih i zabilježenih u glavnoj meteorološkoj postaji u gradu Rijeci. Vremenske neprilike za koje su zatraženi podaci, a koje su karakteristične za klimatsko područje grada Rijeke, su Oborine (≥ 10 mm), Olujni vjetar, Hladni dani (Tmin < 0 °C) i Vrući dani (Tmax ≥ 30 °C). Zatraženi meteorološki podaci su u obliku ukupnog broja dana u mjesecu sa zabilježenim djelovanjem pojedine vremenske neprilike. Ciljevi ovog rada su, primjenom odgovarajućih statističkih testova, testiranje različitosti na razini značajnosti od 5 %, među skupinama vremenskih neprilika (Kruskal-Wallis test, Mann-Whitney test) te, zatim, određivanje 95 % pouzdanog intervala s matematički očekivanim danima zastoja pri radu gradilišta za svaki mjesec pojedinačno (intervalna procjena očekivanja u skupini s normalnom distribucijom podataka). Mjesečni intervali dobiveni statističkom obradom s matematički očekivanim danima zastoja, zbog vremenskih neprilika predstavljaju vrijedan ulazni parametar u svrhu preciznije izrade vremenskog plana i definiranja roka za građenje na području grada Rijeke.Meteorological and climate conditions can significantly affect the continuous and satisfactory progress of work on a construction site. When it comes to creating schedules and defining deadlines at a construction site it is very important to consider possible time delays during work execution as a result of adverse weather conditions. Still, this practice isn\u27t widely applied.  Weather and climate conditions may have different effects depending on the location of the construction site. Hence, to be able to statistically analyze the effect of weather conditions in Rijeka area, with it\u27s moderately warm and humid climate with hot summers (Cfa - Köppen climate classification), data on weather conditions that were measured and recorded in the central meteorological station in Rijeka during the period of last 25 years were requested from the Croatian Meteorological and Hydrological Service (DHMZ). The weather conditions the data was requested on are specific to the microclimate of the Rijeka area. They are as follows: precipitation (≥10 mm), storm winds, cold days (Tmin < 0 °C) and hot days (Tmax ≥ 30 °C). Requested meteorological data are in the form of the total number of days in a month with specific weather conditions recorded. The aim of this paper is to apply appropriate statistical tests in order to examine variations on the scale of significance of 5 % between distinct weather conditions (Kruskal-Wallis test, Mann-Whitney test), and to determine the 95% reliable interval of the mathematical expectation of work delays on a construction site for each month (an interval expectations assessment within a group containing normal data distribution). Monthly intervals obtained via statistical analysis that include mathematical expectation of execution delays due to poor weather condition represent a valuable input parameter for the purpose of creating a more precise schedule and defining construction deadlines in the Rijeka area

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