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The presented paper deals with exponentially growing technology – the Internet of Things (IoT) in the field of healthcare and medicine providing. The goal of the paper is to develop and research a discrete-continuous stochastic model (DCSM) of a functional behavior of a networked healthcare device (in the considered case – an insulin pump) in a form of a structural automaton model (SAM) using the Erlang phase method. It is spoken in the brief details about the healthcare IoT environment, networked insulin pump hazards and behavior with a description of the functional procedures, indicators and parameters of functionality and safety are given. Much attention is aimed at the development process of the DCSM using exponential and Erlang’s distribution laws, description of basic events and structure of a state vector, development of the SAMs. The procedures of validation of the developed models for the exponential and Erlang’s distribution laws are presented and include four research cases to check the relevance of the obtained results. The obtained results show the limit value of the task non-performing probability.

In the development of models of reliability of fault-tolerant systems, one of the tendencies for raising the degree of their sufficiency is accounting real distribution laws for duration of procedures and time intervals between events of processes. Accounting real distribution laws in the model is possible with Erlang phase method. Implementation of this approach implies creation of model of reliability in the form of graphs of states and transitions where number of states is equal to hundreds or thousands. Such approach creates problem of time for the developer. The problem becomes more serious when it is necessary to consider multiple variants of system elements configuration. The article shows method of formalized development of graphs of states which can automatize this process and considerably decrease time consumption.

The development of states-transitions model is an important stage in the technology of the development of the discrete-continuous stochastic models of fault-tolerant systems. There is a known method of developing the states-transitions model, which is based on an algorithm of constructing the state-transitions models out of so-called “structural-automaton model”. This method is implemented in a software tool prototype called “ASNA”. If structural-automaton model is errorless, resulting states-transitions model will be errorless as well. Therefore, there is an actual problem of developing an errorless structural-automaton model. This paper presents the method of developing the structural-automaton models of fault-tolerant systems, which considers alternate outcomes of stochastic processes after completion of switching, recovering and controlling procedures. Presented method allows to develop errorless models as well as to automate laborious procedures.

The article presents the method of the quantitative assessment of the exploitation risk of the navigation information system of air drones. With this method, it's possible to measure the probability of the failure of the system without the development of the failure tree. The presented method provides the way to solve the problem of decreasing the level of the exploitation risks of the navigation information system of the air drone on the stage of the system engineering. Presented method is based on the new mathematical models of the components of the navigation information system with detailed representation of the critical failure state.

Development of states diagram model of the research object is a stage in the technology of building discrete-continuous stochastic behavior models. There is a known method of building states diagram using structural-automaton model. Unlike other known methods, it allows to automate the development of states diagram after changes in research parameters. The most important part in this method is the building of structural-automaton model. This article describes a new approach for solving this task. The key feature of this new approach is the possibility of partial automation.