# Updating Financial Contingency in Execution of Typologically Diverse Construction Projects
## 3 Results  
### Cost Performance Index (CPI) in Diversified Construction Projects  
An inevitable effect of any construction project is deviations from the planned cost and deadline, which are the result of many different factors that can affect the course of the investment process. Having at our disposal accurate data from 41 construction projects, summaries were developed showing in a clear way the magnitude of deviations of cost and deadline from planned values by means of cost performance indices (CPI). Cost performance index (CPI) represents the cost efficiency of a project. It expresses the ratio of the value earned (BCWP) to the actual cost of work performed (ACWP). CPI > 1 means that the project is being implemented cost-effectively, while CPI < 1 indicates budget overruns.  
\[\text{CPI}=\text{BCWP}/\text{ACWP}, \tag{5}\]  
where BCWP--budgeted cost of work performed, ACWP--actual cost of work performed.  
The CPI investment cost realization index is presented in graphs according to the time of investment realization. The results of the analyses are presented by group of projects. A graph of the variation in the cost realization index in the group of residential buildings (M) is shown in Figure 2. Eight projects experienced no deviations. Among the others, the occurrence of higher deviation values was observed in the initial period of their course, which then gradually reduced.  
In the case of the office building group (O) (Figure 3), deviations of the index were observed in 75% of the ventures. The vast majority of the observed deviations were characterized by CPI values greater than 1.  
Figure 3: Variability of the execution rate of the cost of investment in the group of office building group (O).  
Figure 2: Variability in the execution rate of the cost of investment in the group of residential buildings (M).  
The group of hotel buildings (H), for which the results of observations are shown in Figure 4, was characterized by the occurrence of CPI deviations for each project. The overwhelming number of projects showed a high variability of the index value in the range of 0.8-1.05. The values of one project (H.1) significantly deviated from the others, reaching values in the range of 0.67-1.24.  
A group of shopping centres, for which the results are presented in Figure 5, is characterized by a large variation in the CPI cost deviation index. All ventures showed CPI deviations whose course varied strongly in terms of value.  
Figure 4: Variability of the execution rate of the cost of investment in the group of hotel buildings (H).  
Figure 5: Variability of the execution rate of the cost of investment in the shopping centre group (G).  
The last separated group of projects, logistics centres (L), is characterized by the most stable course of CPI values (Figure 6). More than half of the analyzed projects did not show any deviation of CPI during the entire implementation. One investment showed a fluctuating course of CPI values.  
Based on observations of the course of CPI variability in diversified construction projects, the following conclusions and observations were made:  
* The cost performance indexes in the various groups of facilities show great variation both in terms of the values obtained and the observed course;
* The values of the cost performance index are characterized by greater and more chaotic dynamics of variation than the corresponding values of the schedule performance index. This shows the absence of a direct relationship between cost and schedule overruns;
* The course of the values of the individual indicators shown in the charts indicates the values of the CPI at a given, well-defined moment in the life of the investment and does not directly indicate the ultimate cost and schedule overruns of the investment;
* The course of CPI volatility is complex in nature and shows great variation even within groups of facilities. This does not allow any trend to be determined.