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Meeting Real-Time Scheduling Needs


Today, rate-monotonic analysis (RMA) is part of real-time computing textbooks and the only real-time scheduling technology approved by the FAA for Level A avionics software in networked control applications with distributed computers, sensors, and actuators.

The importance of RMA emerged when a software bug caused the computer on the Mars Pathfinder to reset and jeopardized the 1997 mission. Computer scientists patched the software to fix the bug using the rate-monotonic scheduling algorithm. Years before, the SEI was instrumental in the development of the rate-monotonic scheduling paradigm, and its technical staff played a crucial role in the development of the theory.

In 1993, the SEI published A Practitioner's Handbook for Real-Time Analysis: Guide to Rate Monotonic Analysis for Real-Time Systems, which contains quantitative methods that enable real-time system developers to understand, analyze, and predict the timing behavior of many real-time systems. In addition, the SEI created training workshop and consultation services for RMA early adopters.

The SEI (and others') work in RMA transformed real-time engineering practice. Also emerging from the SEI's work in RMA in the following years were two other ideas that underpin contemporary software system development practice: (1) quality attributes influence the shape of the architecture, and (2) the right architecture is fundamental to system success.

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