A Case Study on Formal Verification of Self-Adaptive Behaviors in a Decentralized System

TL;DR

This paper presents a formal verification case study of a decentralized self-adaptive traffic monitoring system using model checking to ensure properties like flexibility and robustness.

Contribution

It introduces a formal architecture model for a decentralized system and verifies self-adaptation properties using timed automata and model checking.

Findings

Verified flexibility and robustness properties of the system

Demonstrated the effectiveness of model checking for decentralized systems

Provided formal guarantees for self-adaptive behaviors

Abstract

Self-adaptation is a promising approach to manage the complexity of modern software systems. A self-adaptive system is able to adapt autonomously to internal dynamics and changing conditions in the environment to achieve particular quality goals. Our particular interest is in decentralized self-adaptive systems, in which central control of adaptation is not an option. One important challenge in self-adaptive systems, in particular those with decentralized control of adaptation, is to provide guarantees about the intended runtime qualities. In this paper, we present a case study in which we use model checking to verify behavioral properties of a decentralized self-adaptive system. Concretely, we contribute with a formalized architecture model of a decentralized traffic monitoring system and prove a number of self-adaptation properties for flexibility and robustness. To model the main processes in the system we use timed automata, and for the specification of the required properties we use timed computation tree logic. We use the Uppaal tool to specify the system and verify the flexibility and robustness properties.