## 3 Research Methodology, Course and Results
### The Course of the Research  
The research has shed light on what problems are most often solved in a systematic manner. First and foremost, these are analyses of variant locations of different development projects. In such cases, decision makers most often use methods based on a multiple-criteria analysis, although the number of steps included may differ slightly, largely depending on the size and complexity of a construction project. Another example of a situation where alternative solutions need to be analysed and selected is a tender, in which the bids are assessed according to previously determined parameters. In a few cases, an analysis of several variants was applied to building material and construction solutions. Detailed data collected during the study and pertaining to decisions made with respect to possible variants of erection of civil structures are presented in Table 3.  
Figure 5: Scheme of research process. Among the analysed civil structures and decision situations connected with their execution, over 40% were road construction projects. Such a large proportion of new roads is the result of the rapidly growing road construction sector stimulated by the EU funds. The second most numerous type of civil engineering projects was the construction of environmental protection facilities. Same as roads, they were mostly built with the contribution of EU funds. Bridges as civil engineering constructions associated with road construction made up 15% of the analysed projects. Each of the remaining types of civil  
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**No. ** & **Type of Investment (Object Function)** & **Quantity** & **No. Object** & **Size \({}^{*}\) (S-Small, M-Medium, L-Large)** & **Number of Sub-Contractors** & **Applied Variant** & **Number of Stages** \\ \hline \hline  & & 1.1. & S & 5 & II & 7 \\ \cline{3-6}  & & 1.2. & S & 6 & II & 8 \\ \cline{3-6}  & & 1.3. & L & 12 & IV & 9 \\ \cline{3-6}  &  
structures corresponded to less than 10% of the total. As many as 4 out of 6 large civil structures represented road structures. Participation in the study each type of objects is presented in the diagram in Figure 6, and the percentage share of various venture in the group of large objects chart in Figure 7.  
The research comprised 6 construction projects classified as large or as highly complex ones. There was the same number of medium-sized and small civil structures (14 civil structures). The percentage of these projects in the total analysed number is illustrated in Figure 8.  
The focus in our study was on decision-making processes which occurred during the execution of the analysed construction projects. A review of the documents made available by the companies supplied a wealth of information about these processes. The models used by the decision makers engaged in the analysed cases most often belonged to model II, i.e., more or less advanced methods of multi-criteria analysis. As many as 25 out of 35 analysed cases took advantage of this model. Some other details regarding the applied models are shown schematically in Figure 8.  
Figure 6: Participation in the study each types of civil structures. Figure 7: Percentage share of various venture in the group of large civil structures. From Figure 9, it is clear that Model 5 was not used in any of the analysed cases of construction projects implementation. It is a model based on more advanced mathematical methods and there is no tradition of using these models by the engineering community. Model 5 has found wide application in enterprises when making decisions related to business strategies. This is due to, inter alia, of the fact that construction companies usually employ people with professional training (marketing and management, economics) that allows them to apply operational research in management-related departments. There is a rather shortage of such people when carrying out the works.