Methodological bases for assessing the impact of construction supervision on the organization of civil engineering production processes

. The formation of conditions for ensuring the established quality of construction objects of various functional purposes is impossible without solving a set of tasks related to the systematic analysis of factors that ensure the organization. Improving the effectiveness of supervisory authorities consists in focusing attention on critical stages of construction and reducing excessive attention to secondary aspects that do not affect the safety of the construction object and do not deviate from the design documentation, in order to reduce the number of inspections and the excessive impact of state supervision in general. The program of inspections of construction supervision is formed on the basis of approved departmental regulations. These rules do not specify quantitative data on the conduct of inspections, nor do they define specific moments of construction of facilities during which it is necessary to conduct a supervisory procedure with a visit to the facility. The current inspection regulations are aimed at identifying deviations from the requirements of project documentation and current regulatory documentation and are not aimed at preventing and preventing the occurrence of critical defects. Necessary to develop a scientifically based methodology for conducting supervisory activities that ensures the formation of high-quality construction products.

The system (subsystem) of state construction supervision is interconnected with the systems (subsystems) of construction management and organization of construction by a single and integral system of construction production [1].
In a complex system (subsystem), it often turns out that correcting the decision made or adapting to the actual conditions of the construction site requires much more money than maintaining specialists and technical departments of the state construction supervision system (subsystem) [2].Exactly because of this reason it is advisable to start the process of monitoring a capital construction object from the earliest periods of the life cycle.
In the structure of the control system, the quality of control actions on the part of state supervision bodies depends on the properties (structure, qualitative and quantitative parameters) of the control system itself.In the vast majority of cases, the process of forming managerial decisions (impacts) is accompanied by the presence of uncertainty in the initial data and the dynamic variability of indicators of the state of the control object.
The presence of a sufficient amount of available, updated and reliable information about the actual state of the construction production system and its individual structural elements is a necessary basis for the development of rational management decisions (impacts) for the formation of the established quality of construction products by all participants in the construction industry [3].
A systematic approach to the collection and storage of information, primarily through the formation of appropriate databases and algorithms for their analysis, makes it possible to provide access to verified and updated information flows necessary for the implementation of investment, urban planning, land management activities, taking into account various groups of stakeholders (authorities, structures , organizations).
The elements of the analysis of production processes of the state construction supervision (GSN) are only types of work that affect the safety of work and the subsequent safe operation of the facility [4].
Statistical data are divided into categories (groups) of absolute and relative indicators [5].The absolute category includes statistical indicators recorded for a certain period of time. of the following types: "the number of damages", "the number of deviations from the design position" or "the number of violations of the organizational and technological sequence of construction".
Сorrelation-regression analysis was used , the methodology of which is used in solving problems in planning, forecasting and analysis in various areas of the national economy [6].
Based on the data using the MS Office " Excel " application package and the graphical method, mathematical models of critical stages of construction were built to improve the efficiency of state construction supervision.
The results of the distribution and construction of mathematical models of the critical stages of construction for the stage of earthworks -the zero cycle -in order to improve the efficiency of state construction supervision are shown in Fig. 1.The results of the distribution and construction of mathematical models of the critical stages of construction at the main stage when arranging the above-ground part of the building to improve the efficiency of state construction supervision are shown in Fig. 2. The results of the distribution and construction of mathematical models of the critical stages of construction for the main stage in the arrangement of internal and external engineering communications in order to improve the efficiency of state construction supervision are shown in fig. 3. The results of the distribution and construction of mathematical models of critical stages of construction for the final period -improvement and commissioning of the facility -in order to increase the efficiency of state construction supervision are shown in Fig. 4. From the above distributions and the constructed mathematical models of the critical stages of construction (Fig. 1-4), we can conclude that there are such periods that require unambiguous control by state bodies.It is at these stages -on specific days of the construction process -that it is advisable to organize a visit by the inspector to the facility under construction.The necessary checks justified in this way will be sufficient to ensure the quality of the construction product.This eliminates the need for other checks, which in this case become redundant.
As a result, thanks to the calculations, it was possible to reduce the total number of inspections, which, of course, will lead to a decrease in production and non-production labor costs of state construction supervision [7].Reasonable inspections will be able to more effectively prevent possible defects, which, ultimately, will lead to a decrease in critical defects received before construction is completed, and therefore to a decrease in the number of refusals issued when issuing conclusions of conformity (AIAs).In turn, reducing the excessive impact of state construction supervision on participants in the construction industry will entail a reduction in the construction period.The absence of unnecessary requirements and instructions from the state construction supervision will not require additional time and resources from the construction participants to eliminate inconsistencies that are not a deviation from the design documentation and, as has already been proven, do not affect the safety of the facility [8].The resources saved in this way will increase the efficiency of organizing the construction of civil facilities.
In addition, in order to apply a risk-based approach in the organization of state construction supervision, risks in this work are usually understood as the total number of violations (defects) at different stages of construction [9].
If we apply the method of multiple linear regression when predicting a continuous value by variables , then the relationship by variables is set using a linear   (1) where are the coefficients of the regression model; is a random variable that is a prediction error.
The parameters of the multiple regression equation can be determined using the least squares method, which minimizes the sum of the squared deviations of the empirical (actual) values of the resulting feature from the theoretical ones obtained using the selected regression equation: (2) where are the actual values of the predicted value (initial values); is the predicted value.
When modeling the number of violations of construction production and structural defects, we assume that the value of the constant component is zero.In this case, this action leads to a violation of one of the Gauss-Markov conditions (on the equality of the mathematical expectation of a random term to zero).However, the equality of the constant component to zero in the generated model of factors leads to a zero value of the number of construction violations.In the presence of a constant component, the number of defects will be equal to the value of the constant component, which does not correspond to objective reality.
The linear regression model of the month or day of violation of the construction stages (the most probable risk) will take the following form: (3) As we can see from the given data, the error of the constructed mathematical models of the most probable risk of violations at the construction stages does not exceed 7.83%, which indicates the possibility of using the developed models in order to reduce the number of inspections of state construction supervision and, accordingly, increase the efficiency of organizing the construction of civil facilities for by reducing unnecessary prescriptions and the cost of eliminating the remarks of the state building supervision [10].
The expected conditions for the formation of a construction system were taken into consideration, taking into account the characteristics of the construction site in the area where the analyzed capital construction object is located [11].
As a result of the practical application of the constructed mathematical models for the critical stages of construction, the following number of checks was obtained, which must be carried out by state construction supervision bodies : Excavation stage: -excavation of the lower layer of soil (cleaning the bottom of the pit) -1 check; Main stage: -arrangement of the foundation base -1 check; -arrangement of structures at the level of 0.000 (to check the entire underground part) -1 check; -arrangement of the above-ground part: -monolithic structures -1 check; -mixed frame -3 checks (installation of the 1st floor, installation of the middle floor, installation of the upper floor); -brick buildings -1 check; -arrangement of internal engineering communications -2 checks; -arrangement of external engineering networks -1 check; Completion of construction: -landscaping and commissioning of the facility -1 check.
The number of inspections of state construction supervision, i.e. the number of arrivals of GOS inspectors is 12 times.
Taking into account the data obtained above on the required number of inspections of the GOS when applying the risk-based approach and the developed mathematical models to improve the efficiency of state construction supervision, the main technical and economic efficiency of the developed model will be as follows: -reducing the labor costs of the GOS; -reduction of non-production costs of GOS; -reducing the production costs of the HOS; -reduction of the construction period by reducing the excessive impact of the GOS and, as a result, increasing the efficiency of organizing the construction of civil facilities by saving resources for the implementation of instructions from the GOS to eliminate inconsistencies that do not affect the safety of the facility and are not deviations from the project documentation.

Fig. 1 .
Fig. 1.Distribution and mathematical models of critical stages of construction for the earthworks stage -zero cycle: 1 -minor defects; 2 -significant defects; 3 -critical defects

Fig. 2 .
Fig. 2. Distribution and mathematical models of the critical stages of construction of the main period in the construction of the above-ground part of the building: 1 -minor defects; 2significant defects; 3 -critical defect

Fig . 3 .
Fig .3. Distribution and mathematical models of critical stages of construction for the main stage of installation of internal and external engineering communications: 1 -minor defects; 2significant defects; 3 -critical defects

Fig. 4 .
Fig. 4. Distribution and mathematical models of critical stages of construction for the final period -improvement and commissioning of the facility: 1 -minor defects; 2 -significant defects