ESOURCE CONSTRAINT PROBLEMS FACED ON CONSTRUCTION PROJECTS AND PROPOSAL FOR BALKAN CONSTRUCTION SECTOR

Considerıng project plans to affect cash flows of construction projects will be aimednecessarily to use constraint resources providing a maximum financial benefit as aresearch study. Resource-constrained project scheduling is the most appropriatemethod of planning of a project activities use limited resources without destroyingtheir precedence relationships. The aim of this study is to propose a solution to theproblem of the time value of cash flows under resource-constrained projectscheduling. For this purpose, cash flows and their net present value graphics of asolid waste transfer station construction project were established under differentscenarios. Dividing into phases of time-based scheduling and resource-constrainedscheduling were compared giving some examples for model and algorithmsanalyzing cash flows and maximum net present value problems, time basedscheduling and resource-based scheduling of a solid waste transfer stationconstruction project was formed. The generated planning were evaluated underdifferent scenarios and examined for different objective functions. The dataobtained from the each scenario were presented with their graphics. These datawere described by comparing the results obtained. The initiation of this study iscaused importantly by the applications of irregular and unmethodicalunderstanding of planning techniques applied in Turkish construction sector. As aresult of this study, scenarios using constrained resources forced less the budgetlimits, but it was observed that it formed lower net present value than the scenarioswhich do not have resource constrained in equal time intervals. This study isproposed to discuss Balkan construction sector projects with the problems of thetime values of cash flows under resource-constrained scheduling

Subcontractor selection practices in international construction projects

This paper presents a study of subcontractor selection practices of Turkish contractors in international projects. The results highlight the current subcontracting practices of main contracting firms that have resulted in a long‐lasting market share abroad. Toward this aim, a detailed questionnaire was administered to 96 construction companies. Turkish and host countries’ subcontractors were shown to be frequently employed in international projects. However, subcontracting firms from other countries were found to not be used. Main contracting companies generally select subcontractors in the periods after the main tender or after the project's start. Although many of them often work with previously known subcontracting companies and do not take into account the lowest bid price as the primary criterion, systematic processes or models are not used to select the best subcontractor. Most importantly, main contractors not only use subcontractors but also carry out activities using their in‐house resources. Hence, this study will not only be a step for further works that can be performed by potential researchers who may find interesting similarities or differences between their countries and Turkey, but also assist contractors who plan to strengthen their positions and to increase work opportunities in the international market. Santrauka Straipsnyje pateikiami Turkijos generaliniu rangovu praktiniai subrangovu parinkimo tyrimai, vykdant tarptautinius pro‐jektus. Akcentuojama dabartine generalinio rangovo imoniu subrangos praktika, kuri sudaro ilgalaike ir plačia rinkos dali. Šiam tikslui buvo išsamiai apklausta iki 96 statybos imoniu. Turkijos ir kitu vadovaujančiaja pozicija užimančiu šaliu subrangovai teige, kad dažnai dirba su tarptautiniais projektais. Tačiau kitu šaliu subrangos imones nedalyvauja toje veik‐loje. Generalines rangovo imones paprastai pasirenka subrangovus pateikus pagrindini pasiūlyma arba projekto pradžioje. Nors daugelis iš ju dažnai dirba su jau anksčiau žinomomis subrangos imonemis ir pasirinkdamos geriausia subrangova neatsižvelgia i pagrindini rodikli‐ žemiausia siūloma kaina, nenaudoja sisteminiu procesu ar modeliu. Svarbiausia, kad generaliniai rangovai naudojasi ne tik subrangovu paslaugomis, bet ir vykdo veikla, naudodamiesi ju turimais vidaus ištekliais. Taigi šis tyrimas bus ne tik potencialiu tyreju žingsnis igyvendinti ir rasti idomiu panašumu bei skirtumu tarp šiu šaliu ir Turkijos, bet ir padeti rangovams stiprinti savo pozicijas bei didinti isidarbinimo galimybes tarptautineje rin‐koje. First Publish Online: 15 Oct 2010 Reikšminiai žodžiai: subrangovai, parinkimas, užsienio projektai, statybos imone