MIMOS: A Deterministic Model for the Design and Update of Real-Time Systems

TL;DR

This paper introduces MIMOS, a deterministic network model for designing and updating real-time systems, enabling flexible modifications and reliable analysis through fixed-point semantics.

Contribution

It presents a fixed-point semantics for a network model of real-time components, supporting deterministic behavior and dynamic updates without altering existing components.

Findings

Deterministic computation of system functions from input streams.

Supports dynamic addition and replacement of components.

Enables efficient model-based analysis and verification.

Abstract

Inspired by the pioneering work of Gilles Kahn on concurrent systems, we propose to model timed systems as a network of software components (implemented as real-time processes or tasks), each of which is specified to compute a collection of functions according to given timing constraints. We present a fixed-point semantics for this model which shows that each system function of such a network computes for a given set of (timed) input streams, a deterministic (timed) output stream. As a desired feature, such a network model can be modified by integrating new components for adding new system functions without changing the existing ones. Additionally, existing components may be replaced also by new ones fulfilling given requirements. Thanks to the deterministic semantics, a model-based approach is enabled for not only building systems but also updating them after deployment, allowing for efficient analysis techniques such as model-in-the-loop simulation to verify the complete behaviour of the updated system.