Using Metrics in the Industrial IoT Value Chain to Drive Trustworthiness
are defined by objectives set for the various
trustworthiness aspects relative to some
metrics, as well as functional and other
business considerations, as illustrated in
Figure 4.
Enhanced Security can reinforce
Reliability: Security of many services in
a system will generally contribute
directly to Reliability objectives – e.g.,
by preventing DOS attacks.
Reliability management techniques
can be detrimental to Security: A
common case of adverse effect on
Security – as previously mentioned - is
the delaying of security updates and
patches in order to preserve the
stability of current IT systems.
Assessing the impact – positive or negative –
of one trustworthiness property on another
property will rely on metrics and related
measurements. The role of metrics goes
beyond assessment though since they also
help manage the reinforcements and
conflicts between trustworthiness aspects
by balancing the metric targets.
Uncovering such dependencies between
trustworthiness aspects is part of a
Figure 4: The Trustworthiness Space as Defined by its Metrics
trustworthiness analysis. Assessing these
dependencies, their synergy and, in case of
conflicts, the acceptable tradeoffs, will rely
on measurements and objectives.
I NTERDEPENDENCY B ETWEEN
T RUSTWORTHINESS AND B USINESS
O PERATIONS
The goal in both design and continued
operation of an IIoT solution is to keep a
system operating within the bounds
determined to be acceptable. These bounds
September 2018
Operational trustworthiness metrics may
inform design and analysis as well as assist in
keeping an operational system in control,
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