TY - JOUR

T1 - RELAX: A Language to Address Uncertainty in Self-Adaptive Systems Requirements

AU - Whittle, Jon

AU - Sawyer, Peter

AU - Bencomo, Nelly

AU - Cheng, B. H. C.

PY - 2010

Y1 - 2010

N2 - Self-adaptive systems have the capability to autonomously modify their behavior at run-time in response to changes in their environment. Self-adaptation is particularly necessary for applications that must run continuously, even under adverse conditions and changing requirements; sample domains include automotive systems, telecommunications, and environmental monitoring systems. While a few techniques have been developed to support the monitoring and analysis of requirements for adaptive systems, limited attention has been paid to the actual creation and specication of requirements of self-adaptive systems. As a result, self-adaptivity is often constructed in an ad-hoc manner. In order to support the rigorous specication of adaptive systems requirements, this paper introduces RELAX, a new requirements language for self- adaptive systems that explicitly addresses uncertainty inherent in adaptive systems. We present the formal semantics for RELAX in terms of fuzzy logic, thus enabling a rigorous treatment of requirements that include uncertainty. RELAX enables developers to identify uncertainty in the requirements, thereby facilitating the design of systems that are, by denition, more exible and amenable to adaptation in a systematic fashion. We illustrate the use of RELAX on smart home applications, including an adaptive assisted living system.

AB - Self-adaptive systems have the capability to autonomously modify their behavior at run-time in response to changes in their environment. Self-adaptation is particularly necessary for applications that must run continuously, even under adverse conditions and changing requirements; sample domains include automotive systems, telecommunications, and environmental monitoring systems. While a few techniques have been developed to support the monitoring and analysis of requirements for adaptive systems, limited attention has been paid to the actual creation and specication of requirements of self-adaptive systems. As a result, self-adaptivity is often constructed in an ad-hoc manner. In order to support the rigorous specication of adaptive systems requirements, this paper introduces RELAX, a new requirements language for self- adaptive systems that explicitly addresses uncertainty inherent in adaptive systems. We present the formal semantics for RELAX in terms of fuzzy logic, thus enabling a rigorous treatment of requirements that include uncertainty. RELAX enables developers to identify uncertainty in the requirements, thereby facilitating the design of systems that are, by denition, more exible and amenable to adaptation in a systematic fashion. We illustrate the use of RELAX on smart home applications, including an adaptive assisted living system.

UR - http://www.scopus.com/inward/record.url?scp=77953026440&partnerID=8YFLogxK

U2 - 10.1007/s00766-010-0101-0

DO - 10.1007/s00766-010-0101-0

M3 - Journal article

VL - 15

SP - 177

EP - 196

JO - Requirements Engineering

JF - Requirements Engineering

SN - 0947-3602

IS - 2

ER -