Aynur Kazaz

Effect of basic motivational factors on construction workforce productivity in turkey

Abstract Human resource today has a strategic role for productivity increase of any organization, and this makes it superior in the industrial competition. With the effective and optimum usage of it, all the advantages supplied by the productivity growth can be obtained. This usage is just possible by establishing clear and understandable criteria for the factors affecting labour. Therefore, it is aimed in this study that the factors influencing construction labour productivity in Turkey are determined, defined, and examined in detail. A survey was applied to 82 firms to obtain required data. According to results, the most effective factors group is organizational factors.

A multiple criteria decision‐making approach to the selection of concrete pumps

Abstract In this study, the ELECTRE III method, which is one of the most common techniques among multiple criteria decision‐making (MCDM) approaches, was considered in a selection problem of concrete pumps. As a methodological framework, a two‐step questionnaire survey was conducted by 70 firms that have and use concrete pumps. A solution of the problem was then found in the light of the real world data by means of ELECTRE III. The paper can be of value to researchers studying the anatomy of decision‐making in equipment selection in general and investigating selection criteria of concrete pumps in particular. It also contributes to the academic environment as an application practice of ELECTRE III to correspond with the nature of equipment selection and as an effective means for the formalization of knowledge possessed by industrial practitioners. On the practical side, ELECTRE III offers an efficient and convenient tool that forces the users into orderly and methodical thinking, and guides them in making...

Causes of Delays in Construction Projects in Turkey

Abstract In both developing and industrialized countries, deviation from a planned time schedule is one of the most frequently encountered problems in construction investments. Various factors faced with during construction period prevent systematic flow of work, which causes time-based anomalies as a conclusion. Considering the vital importance of the construction industry on the macro-economic structure of a country, it is inevitable to be aware of considerable effect of the timely completion on the allocated project budget. In this study, causes of time extensions in the Turkish construction industry and levels of their importance were examined together. In total, 34 factors affecting project duration were taken into account. A questionnaire survey, including these factors, was then applied to 71 construction companies in Turkey, and the outcomes were evaluated by means of statistical analyses. According to the results, “design and material changes” was found to be the most predominant factor, followed...

Health and Safety Perception of Workers in Turkey: A Survey of Construction Sites

This study reports the general health and safety (HS) conditions in the Turkish construction industry from the perspective of construction labor. Toward this aim, a questionnaire survey was carried out with 800 workers employed in 32 construction projects in Turkey. Contractors were found to neglect their legal liabilities in paying workers’ insurance premiums. Also, they overlooked safety training and were reluctant to hiring physicians at construction sites and investing in personal protective equipment (PPE). As the real constructors of projects, workers did not attach adequate importance to occupational training. In addition, they were not willing to use some PPE. Key participants of HS affairs such as workers, contractors, unions, and government should comprehend their drawbacks to overcome the current dangerous view of the industry. In this regard, related government bodies should compel contractors and workers to adapt to the relatively new regulations on occupational HS.

Application of an Expert System on the Fracture Mechanics of Concrete

Expert systems are computer programs that incorporate human expertise to provide advice on a wide range of topics developed from knowledge bases, which contain knowledge collected from all possible sources, mainly with the help of an expert practitioner.The scope of this research is the application of expert system which is considered as a sub-branch of the artificial intelligence systems. In order to achieve this objective, the fracture mechanics of concrete is selected as the application field. With the purpose of determining the fractural behaviour of concrete, various test methods have been developed over the years. However, each method has its own advantages and disadvantages, depending upon the circumstances of the laboratory environment and the required level of information; selection of the most appropriate method could sometimes be a very difficult task. For overcoming this bottleneck as well as to enhance the knowledge of the supervisory staff, an expert-system on the fracture mechanics of concrete has been developed within the context of this paper.The knowledge contained within this expert system has been acquired through an extensive review of the available technical literature and with the information complied, more than a hundred rules were developed. Finally, via the usage of this expert system, the most appropriate testing procedure on the fracture mechanics of concrete has been identified and also further advice related to the subject is supplied to the researcher.

Fuzzy multi-criteria decision making model for subcontractor selection in international construction projects

Abstract.A general contractors ability to select proper subcontractors in foreign projects is a key competitive advantage. Toward this aim, a subcontractor selection model (CoSMo) was developed in this study. As a computational approach, the fuzzy sets method was employed because it can model human judgment by means of linguistic values, combining qualitative and quantitative decision criteria into an aggregate measure. Although the algorithm may be complex for easy acceptance by industrial practitioners, this disadvantage was minimized through a computer-supported system. In order to gain a better understanding of the current practice of CoSMo, a real world construction project was conducted. As a result, it was observed that CoSMo has high practical application and can be used as an advisory system by satisfying principal contractors requirements to reduce the risk involved in the selection of a subcontractor. Moreover, it gives an initial idea of how subcontractors perform on each decision criterion ...

Quality function deployment in the speculative house-building market: how to satisfy high-income customers

This paper presents a study that reports a detailed process of ‘quality function deployment’, considering an ultra-luxury villa project. It is based on a questionnaire survey that was applied to 42 residents and seven top managers. The results highlight real expectations of high-income residents. Residents were not satisfied with the ‘sauna’, ‘sports areas’, and ‘fitness centre’ despite the fact that these were among the least important expectations. However, residents were satisfied with the ‘security of the complex’, ‘architectural design’, and ‘quality of the end-products’. If some expectations (i.e. ‘areas for common use’, ‘playing areas for children’, and ‘quality of the end-products’) achieve better technical standards in the next projects, demand for luxury residences will likely be improved. Consequently, 25 expectations and corresponding findings constitute a preliminary framework for an expectations agenda for such projects for builders who wish to improve marketing practices.

Quantification of fresh ready-mix concrete waste: order and truck-mixer based planning coefficients

ABSTRACT This paper reports a study of order and truck-mixer based planning coefficients used to avoid or utilise fresh concrete waste. To achieve this objective, an original calculation procedure was proposed to quantify the fresh concrete waste, and direct quantitative measurements were performed in three batching plants in Turkey. Data obtained were analysed by descriptive statistics, one-way analysis of variance, and hypothesis testing. As a result, clients may order 8.57% more of their concrete needs instead of using much wider margins to avoid over-ordered concrete. They may also reserve 8.96% of their concrete needs in other batching plants to compensate their possible extra concrete requirements. Based on these numbers, concrete amount and cost may be better estimated, and thus, the over-ordered concrete may be eliminated. Finally, leftover concrete amount was found to be 0.33% of total concrete in a truck-mixer and to be in a relationship with the number of arrivals of a truck-mixer in an order. Through these findings, potential conflicts between contractors and concrete suppliers about the amount of delivered concrete may be prevented. Also, batching plants may save concrete and benefit from recycling. Overall, natural resources and energy may be consumed less and environmental pollution may be prevented.

Uluslararası İnşaat Projelerinde Taşeron Seçimi İçin Karar Kriterleri

Dusuk kaliteli taseronlar tarafindan yurutulen uluslararasi bir insaat projesi, cogunlukla zaman ve masraf asimlarina, yeniden islere, catismalara ve musterilerin memnuniyetsizligine yol acmaktadir. Bu nedenle, bu makale, uluslararasi insaat projelerinde taseron secimi kriterleri uzerinde yapilmis bir calismayi sunmaktadir. Bu amaca yonelik olarak, Turk Muteahhitler Birligi uyesi olan 96 insaat firmasina derinlemesine bir anket uygulanmistir. Sonuclar, ankete katilan kisilerin algilanan onemini ortaya cikarmak icin kullanilan siralama yontemi ile analiz edilmistir. Tercihleri ​​bir anket ile degerlendirmek uyelik degerlerini bulanik bir degiskene atamak icin kullanilabilir oldugundan, alt yuklenici secim kriterleri ve asamalari icin bulanik onem agirliklari ve siralamalari elde edilmistir. Bu baglamda, uc asamali kavramsal bir secim proseduru, ozel olcutleri ile birlikte, onerilmistir. Sonucta, ilk asama olarak on-secim, sirasiyla genel ve benzer proje tecrubesi, gecmiste beraber calisilmasi, kisisel iliskinin varligi, mevcut ve muhtemel is yuku, sayginlik, gecmis projelerdeki hukuki davalar, gecmis projelerdeki performans duzeyi, finansal kapasite, merkez ofisten uzaklik, gecmisteki is guvenligi performansi gibi on kriterden olusur. Muzakere asamasi, iletisim duzeyi, guvenilirlik, sorunlara cabuk yanit verebilirlik, projeyi kavrama, ozverili calisma, proje icin duyulan istek, kalite algilamasi gibi yedi kriter icermektedir. Son olarak, son secim asamasi odeme plani, teklif fiyati, isgucu, teknik personel, ekipman, alt yuklenici calistirma yuzdesi, gecikme tazminati miktari gibi yedi kriteri icerir. Sonuc olarak, bu calisma, insaat sektorundeki arastirma ve uygulamalari, arastirmacilarin, endustriyel uygulayicilarin ve muteahhitlik organizasyonlarinin bakis acisindan sunmak icin onemli bir potansiyele sahiptir.