Complex methodology for determining WCET in modeling real-time system operation processes

The analysis of modern approaches used to determine the maximum allowable time required to perform a set of tasks based on the parameters of the information system has been conducted. The classification of real-time systems has been carried out, and the peculiarities of designing, implementing, configuring, and adapting functional components and architecture of the overall complex in accordance with worst-case execution time (WCET) estimation have been identified. A multilevel classification of tasks performed in RTS environment has been constructed, including (i) classification according to task type; (ii) classification according to execution time characteristics; (iii) classification according to task execution priority; (iv) classification according to system flexibility level; (v) classification according to criticality level; (vi) classification according to hardware-software platform architecture. For representation purposes within mentioned function regarding periodic and sporadic tasks such variables as start moment defining first iteration start moment for executing a set-task are introduced together with time interval defining gap between set-task iterations as well as time range defining set-task iteration execution process. As a result, scheduling algorithm creates list of tasks corresponding to scheduling scenario describing sequence processing order completion moments at each iteration basis which defines sets’ iteration start-completion moments together with statistical indicators characterizing nature or processing completion moments.