Architecture Level Safety Analyses for Safety-Critical Systems

Abstract

The dependency of complex embedded Safety-Critical Systems across Avionics and Aerospace domains on their underlying software and hardware components has gradually increased with progression in time. Such application domain systems are developed based on a complex integrated architecture, which is modular in nature. Engineering practices assured with system safety standards to manage the failure, faulty, and unsafe operational conditions are very much necessary. System safety analyses involve the analysis of complex software architecture of the system, a major aspect in leading to fatal consequences in the behaviour of Safety-Critical Systems, and provide high reliability and dependability factors during their development. In this paper, we propose an architecture fault modeling and the safety analyses approach that will aid in identifying and eliminating the design flaws. The formal foundations of SAE Architecture Analysis & Design Language (AADL) augmented with the Error Model Annex (EMV) are discussed. The fault propagation, failure behaviour, and the composite behaviour of the design flaws/failures are considered for architecture safety analysis. The illustration of the proposed approach is validated by implementing the Speed Control Unit of Power-Boat Autopilot (PBA) system. The Error Model Annex (EMV) is guided with the pattern of consideration and inclusion of probable failure scenarios and propagation of fault conditions in the Speed Control Unit of Power-Boat Autopilot (PBA). This helps in validating the system architecture with the detection of the error event in the model and its impact in the operational environment. This also provides an insight of the certification impact that these exceptional conditions pose at various criticality levels and design assurance levels and its implications in verifying and validating the designs.

Safety Assessment of the Reconfigurable Integrated Modular Avionics Based on STPA

“…Great attention has been paid to the safety of the dynamic reconfiguration system, but a feasible safety assessment theory has not been reestablished. NASA's Langley Research Center proposed a solution which added an independent decision module to the IMA system to monitor sharing independence among the applications of avionics resources [7]; The thesis [8] proposed a method for analyzing the impact of interrupt correlation using the AADL model. The thesis [9] inverted the risk of redundant sequences in the cumulative transmission of the AFDX protocol; an analysis was carried out, and a method to mitigate this risk by limiting the transmission length was proposed.…”

Research on the Reliability Analysis of the Integrated Modular Avionics System Based on the AADL Error Model

“…The error model annex [4] is a state machine that can be associated with an AADL component or connection, to describe system errors, error behavior, and error propagation [5]. Including…”

“…The interaction between hardware and software [8] is shown in Figure 5 properties//random events properties explaination occurrence=>poisson os applies to fail; occurrence=>poisson os applies to detection; occurrence=>fixed dd applieds to direct_damage; occurrence=>fixed 1-dd applies to performance_degradation; occurrence=>fixed phi applies to unremovable; occurrence=>fixed 1-phi applies to removable; occurrence=>poisson mu applies to restart; occurrence=>poisson td applies to time_damage; occurrence=>poisson theta applies to recovery; Figure 4: Single software error model. 4 International Journal of Aerospace Engineering ensures that they do not have the influence on each other. However, because of the needs for communication between applications, the errors may be transferred across different partitions during the data transmission and may damage the partition [9].…”

A Step-by-Step Procedure for Tests and Assessment of the Automatic Operation of a Powered Roof Support

“…The selection of technical parameters of machines and equipment is important due to the arduous conditions in which they will work. It is possible to evaluate correctly selected machines through active monitoring of their operating parameters and analysis of operating conditions [33][34][35][36][37][38][39]. One of the main sources of hazards causing accidents at work in mining plants is the technical infrastructure and, in particular, machinery and technical equipment.…”