The Unmet Challenge of Timed Systems

Maler, Oded

doi:10.1007/978-3-642-54848-2_12

Cited by 3 publications

(1 citation statement)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The use of formal specifications for defining the functional safety properties of such systems has been widely recommended in most industrial standards, including aeronautics (DO-178C), automotive (ISO 26262), industrial process automation (IEC 61508), nuclear (IEC 60880), railway (EN 50128) and space (ECSS-Q-ST-80C), specifically for those functionalities that require a high safety-integrity level. Although reliability and fault tolerance are as important attributes of the system design as functional correctness [6,8,9,11,27,34], or performance attributes such as timing [1,2,12,13,33], power [17,18] and security [22], formal specification of reliability, especially with respect to the critical functional safety properties has so far received very little attention. This is largely due to the perception that reliability and fault tolerance need to be addressed at the platform level, not at the functional level [20,40].…”

Section: Introductionmentioning

confidence: 99%

Early-Stage Resource Estimation from Functional Reliability Specification in Embedded Cyber-Physical Systems

V.¹,

Hazra²,

Dasgupta³

et al. 2020

Preprint

View full text Add to dashboard Cite

Reliability and fault tolerance are critical attributes of embedded cyber-physical systems that require a high safety-integrity level. For such systems, the use of formal functional safety specifications has been strongly advocated in most industrial safety standards, but reliability and fault tolerance have traditionally been treated as platform issues. We believe that addressing reliability and fault tolerance at the functional safety level widens the scope for resource optimization, targeting those functionalities that are safety-critical, rather than the entire platform. Moreover, for software based control functionalities, temporal redundancies have become just as important as replication of physical resources, and such redundancies can be modeled at the functional specification level. The ability to formally model functional reliability at a specification level enables early estimation of physical resources and computation bandwidth requirements. In this paper we propose, for the first time, a resource estimation methodology from a formal functional safety specification augmented by reliability annotations. The proposed reliability specification is overlaid on the safety-critical functional specification and our methodology extracts a constraint satisfaction problem for determining the optimal set of resources for meeting the reliability target for the safety-critical behaviors. We use SMT (Satisfiability Modulo Theories) / ILP (Integer Linear Programming) solvers at the back end to solve the optimization problem, and demonstrate the feasibility of our methodology on a Satellite Launch Vehicle Navigation, Guidance and Control (NGC) System.

show abstract