IMRRA identifies key three vessel safety and security risk factors: Static, Dynamic and Verified.

Each safety risk factor is classified and given a numerical weighting.

**1. Statistical Risk Factors** are vessel criteria that do not significantly vary over time and are associated with longer-term vessel safety performance.

**2. Dynamic Risk Factors** arise from safety risk events, their frequency, and severity.

**3. Verified Risk Factors** Physical inspections are recommended to be incorporated into the vessel's risk rating assessment.
Verified high standards of vessel management and operation will improve the vesselâ€™s safety risk rating.
A decline or improvement in vessel management and operation over time will have an adverse effect on vessel ratings.

**IMRRA's Vessel Risk Assessment Methodology** is based on a function of several variables reflecting the statistical data.
IMRRA utilizes the method of regression analysis, that is the law of large numbers where "the average of a large number of independent measurements of a
random quantity tends toward the theoretical average of that quantity", resulting increasing accuracy with data accumulated.

Risk assessment is an essential part of many general risk management systems. It is a process of quantitative & qualitative determination of risk magnitude. One part of the general risk assessment system is a 'risk rating'.

Risk rating (percent of risk) is a risk classification with quantitative & qualitative indicators, interpolated through comparing the static, dynamic and verified risk factors of a ship directly related to safety and security.

IMRRA implements the Fractal Theory to increase the reliability of forecasting risks and threats. Using the principle of fractal theory opens up new possibilities in modelling risk assessment processes. The key point is the self-development of the fractal, as a mathematical object, which is most consistent with the systemic nature of the processes occurring under conditions of nonlinear dynamics of the external and internal environments.

The method assumes that all the factors are equally important. However, the division of Risk Factors enables us to weigh and emphasize the factors that are more significant for risk assessment, and identify the key "driving" factors that are controlling the result.

The Risk Rating is a calculated number that results from a sum of four basic functions:

**G(A)=(F1(A)*B1+F2(A)*B2+F3(A)*B3+F4(A)*B4)/(B1+B2+B3+B4)**

F1 = (a1*b1+a2*b2+...+an*bn)/(b1+...+bn) (weighted average on all key factors)

F2 = a1C1+..+anCn+C0 (correlation of key factors with other factors)

F3 = (a1b1a2b2...anbn)1/(b1+b2+...bn) (geometric mean used for verification of factors)

F4 = 1-(1-a1)(1-a2)(1-a3)...(1-an) (levels of confidence for dependent variables)

Where Ci form a vector equal to (XTX)-1XY, where X is the matrix formed by the input data for all data samplings, and the vector Y is formed from the corresponding results of data verification

Bi=sum(Fi(Aj)-Yj)2

Note: F may use various methods for calculating A, that is F1-1 is not equal to F2-1
IMRRA's risk ratings determines the likelihood of the ship is safe enough to continue working, or whether additional control measures are required to eliminate the risks.