ИСТИНА

The models arising in such applications as insurance, inventory, telecommunications, finance, population dynamics and others are of input-output type. Hence, another interpretation of these elements lets pass from one applied domain to another. Discrete-time models became popular during the last decade because in some situations they give a more appropriate description of system functioning. Therefore we consider two models (discrete- and continuous-time ones) in the framework of reliability and cost approaches, study their limit behavior, stability and reliability.