|
2008 ARS, India
Track 2 Session 4
Reliability Estimation of Single Shot
Missile Systems - Challenges and Approach
In modern times, the defence
forces of every country aspire to obtain a weapon system
that has a single shot kill probability of 99.9% and more. Thus,
"Fire & Forget" type missiles are in vogue and have become the
order of the day. Such a single shot missile system is a highly
complex system, composed of state-of-the-art
subsystems/packages effectively and efficiently packed in a
strong, aerodynamically perfect but lightweight, airframe.
To achieve such a weapon system, it need not be emphasized that
each and every subsystem/package must be highly reliable,
meeting the requirements of Six Sigma. Therefore, in-depth
reliability study and failure analysis have become inevitable to
accurately predict the overall missile reliability and achieve
the desired single shot kill probability. The challenges in
estimating the magic figure of missile reliability are colossal.
The major impediments that a reliability engineer encounters are
the non-availability of a frozen configuration of the missile
system, limited number of units available for tests,
non-availability of time to failure, limited test data with no
failures, operating time criticalities varying from milliseconds
to seconds and the single shot nature of many subsystems and subsubsystems, which add on to complicate the issues.
This presentation describes endeavors to bring about “built-in”
reliability and quality in the basic design of subsystems
through design reviews at appropriate levels, testability
studies, FMEA/CA studies, Fault Tree Analysis (FTA), Reliability
Demonstration Tests (RDT), Failure Analysis Boards (FAB) and
Reliability Growth Analysis.
Key Words: Reliability, Missile, Life Testing, FMEA,
FMECA, FTA, Reliability Growth, Environmental Tests
Divya Prakash Joshi
Defence Research
& Development Laboratory |
|
|
