posted on 2013-11-18, 15:15authored byKathryn S. Stockwell
There are many methods for modelling the reliability of systems based on component failure
data. This task becomes more complex as systems increase in size, or undertake missions
that comprise multiple discrete modes of operation, or phases. Existing techniques require
certain levels of expertise in the model generation and calculation processes, meaning that
risk and reliability assessments of systems can often be expensive and time-consuming.
This is exacerbated as system complexity increases.
This thesis presents a novel method which generates reliability models for phasedmission systems, based on Petri nets, from simple input files. The process has been
automated with a piece of software designed for engineers with little or no experience
in the field of risk and reliability. The software can generate models for both repairable
and non-repairable systems, allowing redundant components and maintenance cycles to be
included in the model.
Further, the software includes a simulator for the generated models. This allows a user
with simple input files to perform automatic model generation and simulation with a single
piece of software, yielding detailed failure data on components, phases, missions and the
overall system. A system can also be simulated across multiple consecutive missions. To
assess performance, the software is compared with an analytical approach and found to
match within 5% in both the repairable and non-repairable cases.
The software documented in this thesis could serve as an aid to engineers designing
new systems to validate the reliability of the system. This would not require specialist
consultants or additional software, ensuring that the analysis provides results in a timely
and cost-effective manner.
Funding
Department Studentship
History
School
Aeronautical, Automotive, Chemical and Materials Engineering