Mitigating the obsolescence of quality specifications models in service-based systems


Requirements-aware systems address the need to reason about uncertainty at runtime to support adaptation decisions, by representing quality of services (QoS) requirements for service-based systems (SBS) with precise values in run-time queryable model specification. However, current approaches do not support updating of the specification to reflect changes in the service market, like newly available services or improved QoS of existing ones. Thus, even if the specification models reflect design-time acceptable requirements they may become obsolete and miss opportunities for system improvement by self-adaptation. This articles proposes to distinguish "abstract" and "concrete" specification models: the former consists of linguistic variables (e.g. "fast") agreed upon at design time, and the latter consists of precise numeric values (e.g. "2ms") that are dynamically calculated at run-time, thus incorporating up-to-date QoS information. If and when freshly calculated concrete specifications are not satisfied anymore by the current service configuration, an adaptation is triggered. The approach was validated using four simulated SBS that use services from a previously published, real-world dataset; in all cases, the system was able to detect unsatisfied requirements at run-time and trigger suitable adaptations. Ongoing work focuses on policies to determine recalculation of specifications. This approach will allow engineers to build SBS that can be protected against market-caused obsolescence of their requirements specifications.

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Divisions: ?? 50811700Jl ??
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Event Title: 2nd IEEE international workshop on model-driven requirements engineering
Event Type: Other
Event Dates: 2012-09-24
Uncontrolled Keywords: requirements-awareness,quality of service,service-based systems,dynamically adaptive systems,requirements model,model@runtime
ISBN: 978-1-4673-4387-9, 978-1-4673-4389-3, 978-1-4673-4388-6
Last Modified: 04 Jan 2024 08:31
Date Deposited: 01 Jul 2013 08:42
Full Text Link: http://ieeexplo ... rnumber=6360076
Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
PURE Output Type: Conference contribution
Published Date: 2012
Authors: Torres, Romina
Bencomo, Nelly (ORCID Profile 0000-0001-6895-1636)
Astudillo, Hernan



Version: Accepted Version

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