Resilient Critical Infrastructure Management using Service Oriented Architecture: A Test Case using Airport Collaborative Decision Making

The SERSCIS approach aims to support the use of interconnected systems of services in Critical Infrastructure (CI) applications. The problem of system interconnectedness is aptly demonstrated by ‘Airport Collaborative Decision Making’ (A-CDM). Failure or underperformance of any of the interlinked ICT systems may compromise the ability of airports to plan their use of resources to sustain high levels of air traffic, or to provide accurate aircraft movement forecasts to the wider European air traffic management systems. The proposed solution is to introduce further SERSCIS ICT components to manage dependability and interdependency. These use semantic models of the critical infrastructure, including its ICT services, to identify faults and potential risks and to increase human awareness of them. Semantics allows information and services to be described in such a way that makes them understandable to computers. Thus when a failure (or a threat of failure) is detected, SERSCIS components can take action to manage the consequences, including changing the interdependency relationships between services. In some cases, the components will be able to take action autonomously — e.g. to manage ‘local’ issues such as the allocation of CPU time to maintain service performance, or the selection of services where there are redundant sources available. In other cases the components will alert human operators so they can take action instead. The goal of this paper is to describe a Service Oriented Architecture (SOA) that can be used to address the management of ICT components and interdependencies in critical infrastructure systems

Pre-Runtime Planning of a Reliable Real-Time Communication System

During the past few years computer systems have been applied to many safety critical application domains. In such applications a failure in the controlling computer system might result in catastrophic consequences such as loss of human life. Most of these systems are distributed and thus based on a reliable communication system. Toprovide utmost dependability a communication system offering both real-time and fault-tolerance capabilities is required. The Time

An Evolutionary Approach to Multiprocessor Scheduling of Dependent Tasks

The scheduling of application tasks is a problem that occurs in all multiprocessor systems. This problem becomes even more complicated if the tasks are not independent but are interrelated by mutual exclusion and precedence constraints. This paper presents an approach..

SERSCIS: Semantic Modelling of Dynamic, Multi-Stakeholder Systems

This paper describes a novel approach to semantic system and security modelling developed in the SERSCIS project. The approach is designed to address dynamic multistakeholder systems that are composed from services at run-time. This presents several challenges for security risk modelling and management that are not well addressed by previous work. The biggest challenge is the fact that at design-time one only knows the structure but not the composition of the system, forcing an abstract modelling approach to be used. The SERSCIS approach deals with this by defining a set of OWL classes describing generic system assets, threats and security controls and the relationships between them. This dependability model captures security expertise concerning the types of threats that can arise in general and the controls that can be used to address them. An abstract system model can then be created using OWL subclasses, to capture the types of assets and their relationships in a specific system, but still without specifying how many assets, where they are deployed or what security controls they have. The resulting models can be used as inputs to run-time semantic monitoring tools, where the knowledge encoded in the abstract system model is used to automatically determine system threat activity and system vulnerabilities. The approach was validated in an Airport Collaborative Decision-Making scenario

The Cluster Compiler - A Tool for the Design of Time-Triggered Real-Time Systems

An off-line planning tool that supports the programmer in developing his real-time application is mandatory in the design of time-triggered real-time systems. This paper describes the architecture and the functions of such a tool, the Cluster Compiler, that is in development at our institute. We emphasize on the principle of a strict separation of the local from the global parts of a distributed system and on the consequences for the structure of the design tool arising from this principle. Introduction At present, real-time systems are often designed unsystematically. Conventional software modules are integrated by "real-time specialists" who tune the system parameters (e.g., task priorities, buffer sizes, etc.) during an extensive trial and error period, consuming more than 50% of a project's resources. Why the system performs its functions at the end is sometimes a miracle, even to the "real-time specialists". To change this deplorable situation we need a proper real-time system ar..

Configurable Time-Redundant Task Execution for Fault-Tolerant Real-Time Systems

The design of fault-tolerant real-time systems is characterized by a trade-off between performance considerations and fault-tolerance aspects. This paper presents a design approach that provides three strategies for time-redundant execution of the tasks of an application. The three execution strategies differ in their faulttolerance and performance properties such that a software designer can tailor the structure of the application software to the performance and fault-tolerance needs of an application. The paper describes the three time-redundant execution strategies and compares them with respect to fault tolerance, CPU-time requirements, and schedulability

Solving NP-Complete Problems in Real-Time System Design by Multichromosome Genetic Algorithms

Most problems in the design of real-time applications like task allocation or scheduling belong to the class of NP-complete problems and can be solved efficiently only by heuristics