Five-Valued Reliability-Oriented Operational Modeling of an Internal Combustion Engine

Modeling of the operational process of technical objects, particularly complex and intelligent systems, constitutes one of the key challenges of contemporary technical diagnostics. Such models play an important role both at the design stage of technical systems and in decision-making processes related to maintenance and evaluation of operational performance. In classical approaches, the analysis of possible operating modes of a technical object is typically based on a finite set of discrete states, which often proves insufficient to describe intermediate degradation stages and interaction-driven effects occurring during real operation. The model presented in this paper enables a comprehensive analysis of the operational process of complex technical objects by explicitly accounting for intermediate technical states and their influence on system behavior. By employing state probability functions and technical availability functions within a five-valued diagnostic framework, the proposed approach supports modeling of the operational process at an early design stage, assessment of compliance between actual operation and expected maintenance schedules, and evaluation of potential operational outcomes. As a result, the model provides a more detailed and realistic basis for reliability assessment of complex technical systems, particularly in situations where gradual degradation and subsystem interactions play a significant role. The proposed approach can be directly applied to a wide class of complex engineering systems characterized by interacting subsystems and progressive degradation processes, supporting reliability-oriented design and maintenance optimization under real operating conditions.