Environmental Engineering Reference
In-Depth Information
In requirement specification for creation
(modernization) of the I&C systems require-
ments on personnel, premises, quality of primary
power supply, organizational protective actions
against unauthorized access, tests, acceptance
and maintenance of the system on the operating
site and others can be also specified. Quite often
modification covers not the I&C system as in
whole, but only some of its part. In this case RS
can be issued for development and implementation
of only this part, e.g.: core (i.e. SHC), separate
hardware and software.
In specification requirement for development,
production and delivery of the SHC, at least, the
following requirements are regulated:
cal, electric, electromagnetic) in operation and
extreme conditions are regulated.
In RS on the SHC requirements on production,
factory tests and acceptance, marking, packag-
ing, transportation and storage of components,
manufacturer's guarantees and other typical for
manufacturing production should be determined.
Stage 3:
Design, production and testing of the
I&C components at the enterprise.
At this stage, as the level of detail increases,
the assessment of obtained results is performed.
During this stage required changes can be made
in earlier approved technical decisions until
stepwise approximations will achieve system
configuration, satisfying standards and rules of
NRS, initial data and customer's requirements and
RS requirements on system creation (moderniza-
tion). After the design process achieves such a
detail level, when it is known how the specified
functions will be performed, what new (developed
specially for the designed system), replicated and
industrial components will be applied and how
these components should be configured, project
documentation, including ordered specifications
on equipment procurement, is issued.
During the process of the SHC development
a composition, structure and distribution of
functions among its components are determined;
possibility and reasonability of the use of earlier
developed hardware are assessed; make a solution
about the use of borrowed (replicated) and com-
mercial items; chose elemental and constructive
base for new components that should be developed
for the SHC. Made technical decisions can be
corrected at further stages, taking into account
technical and economic reasonability and on the
basis of assessment of their compliance with
requirements of regulatory documents and RS.
Software of the SHC is developed and verification
is performed at all stages of their creation - during
formulation of initial data, design, coding, inte-
gration with hardware. According to NP, 2005,b,
•
For the main and additional functions;
•
For reliability, tolerance, quality, indepen-
dence of performed functions;
•
For software and dataware;
•
For safety substantiating documents;
•
For development and production quality
assurance;
•
For assessment and justiication of compli-
ance at all stages of life cycle.
For each of the performed functions the fol-
lowing are specified in RS: purpose; a list of
controlled parameters, events and conditions;
variation ranges and limits of probable values of
controlled parameters; types of input and output
signals; relation between inputs and outputs (in
the form of formulas, tables or algorithms); other
data required and sufficient for performance of
the function. In RS a reserve of equipment and
computer power of the SHC required for provision
of a possibility for system modernization, when
functional requirements change (extend) at further
life cycle stages, and also for compensation of oc-
curred faults if the replacement of failed element is
temporarily impossible or unreasonable, is usually
provided. For all independently operating parts of
the SHC requirements of tolerance or resistance
to external influences (environmental, mechani-
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