Unformatted text preview: n)
to the software verification program. IV&V is a
process whereby the products of the software
development life cycle are independently reviewed,
verified, and validated by an organization that is
neither the developer nor the acquirer of the software.
The IV&V agent should have no stake in the success
or failure of the software; the agent’s only interest
should be to make sure that the software is thoroughly
tested against its requirements.
IV&V activities duplicate the project’s V&V
activities step-by-step during the life cycle, with the
exception that the IV&V agent does no informal
testing. If IV&V is employed, formal acceptance
testing may be done only once, by the IV&V agent. In
this case, the developer formally demonstrates that
the software is ready for acceptance testing. Operational and Disposal Verification Operational verification provides the assurance
that the system functions properly in a (near-) zero
gravity and vacuum environment. These verifications
are performed through system activation and operation,
rather than through a verification activity. Systems that
are assembled on-orbit must have each interface
verified, and must function properly during end-to-end
testing. Mechanical interfaces that provide fluid and gas
flow must be verified to ensure no leakage occurs, and
that pressures and flow rates are within specification.
Environmental systems must be verified. The
requirements for all operational verification activities are
defined in the VRSD.
Disposal verification provides the assurance
that the safe deactivation and disposal of all system
products and processes has occurred. The disposal
stage begins in Phase E at the appropriate time (i.e.,
either as scheduled, or earlier in the event of premature
failure or accident), and concludes when all mission
data have been acquired and verifications necessary to
establish compliance with disposal requirements are
finished. Both operational and disposal verification
activities may also include validation assess- NASA Systems Engineering Handbook
Integrating Engineering Sp...
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