The issue of engineering systems safety in particular of vertical transportation is revealed. Inconsistency in the implementation of theoretical developments in practice is defined because of the probabilistic calculation of the parameters modeled by monotone-logical functions, when real systems are non-monotone functions. The duality of the results of the processes theoretical description is revealed. A typical algorithm of safety analysis is based on the deductive abilities of a researcher when drawing up a scenario of possible hazardous situations, their development and possible consequences. Critical analysis of the regulated risk assessment procedures FMEA / FMECA was carried out when compiling the criticality level matrix of the event or process. Conceptually, the risk analysis is represented by a sequence of logical steps that provide a systematic approach to the identification of hazards associated with the operation of vertical transportation. It is suggested to supplement the methodology for data records of the loss time during the nonproduction downtime with the safety parameter assessment. The condition of the vertical transportation systems and the parameter deviation vector in the dual risksafety system are established by introducing a variable value of the parameter in the probabilistic polynomial of the simulation event model. The obtained result is universally applicable, which allows us to approach to the value of the simulated criticality of the parameter through the variability of the calculations. The developed method imposes constrains on the compilation of a logical chain of assumptions in the program of the experimental research. It also allows creating adequate conditions for the operating of the physical model of the system. The modified methodology suggests table compiling of the parameter variation limits ranging the hazard rate and calculating the corresponding values of hazard factors. It is suggested to apply the developed methodology as the supplement to the existing general methodology for risk assessment at all stages of the service time of vertical transportation. The example of the implementation of the modified procedure. The developed service life parameter adjusting method reduces operation costs, ensures safety and stability of the public mobile movement abilities when using vertical transportation.