Analysis of event-triggered and time-triggered architecture for a reliable embedded system

Develop any safety critical system (Automotive, Aerospace, and Medical) requires highly sophisticated software architecture and design patterns. Recent international standards and guidelines also concern about it. Traditional Event Triggered (ET) architecture is not predictable in nature due to the presence of sporadic events and asymmetric interrupts. So after developed, testing and validation of the system becomes very complex. Time Triggered (TT) architecture is predictable because it is not dependent on the sporadic events. In TT approach, system behavior is known at every point in time. In TT approach, blocking of Tasks and Asymmetric interrupts are not allowed. In this work, we've implemented a Safety Critical Real-Time Prototype using both approach and compares it. This paper describes the merits and demerits of both ET and TT approach. At the end, we also implemented TT design patterns using RTOS that is basically an ET framework.