The systematic development of fault-tolerant real-time systems with guaranteed timeliness requires an appropriate system architecture and a rigorous design methodology. Those services of the architecture that help to simplify the work of the real-time programmer are described, taking the MARS architecture as an example. Programming in the large activities, i.e., the systematic derivation of task timing parameters from the requirements specification, are then addressed. Programming to meet a time budget is discussed, and the programming interface, the programming environment, and the testing and support tools are presented. The architecture and most of the tools have been implemented and can be demonstrated on a fault-tolerant prototype application.>

The authors propose a system architecture, MARS, which supports a strict separation of the issues of synchronization and timeliness, data transformation, and the dependability aspects (e.g., error detection, error handling, and redundancy management. The systematic development of fault-tolerant real-time systems with guaranteed timeliness requires an appropriate system architecture and a rigorous design methodology. The authors propose a system with strict separation of the issues of synchronization, dependability aspects, and data transformation. Dependability aspects are handled by the architecture. Synchronization and programming in the large are handled at the design level. The programmer only has to be concerned with a sequential program for which he has to meet a so-called time budget. The architecture and many tools have been implemented and can be demonstrated on a fault-tolerant prototype application.>

In constructing highly reliable LAN systems, a mechanism that enables every active node to maintain timely and consistent knowledge about the health status of all cooperating nodes can be used as a cornerstone. The authors consider the case where maintenance of such knowledge is achieved in a decentralized manner and timely and consistent recognition of newly joining nodes is also facilitated. The authors develop an optimal version of H. Kopetz et al.'s (1985) periodic reception history broadcast (PRHB) method. The authors' version enables detection of failures with minimum latency and is called the PRHB with earliest detection (PRHB/ED). This scheme has much shorter latency than the previous PRHB scheme and is yet equally practical in the sense that it does not increase the communication traffic at all, and the complexity of the algorithm for analyzing the observations exchanged among the active nodes is still bounded by a linear function of the number of nodes in the system.>