Gsoe9840 Assignment2

GSOE9840 – Session 2 / 2012 – Reliability Assignment

Due – Week 13

The nose-wheel landing system of a commuter jet contains two critical components: A shock absorber (Component A) and bearing assembly (Component B). A failure of either component is considered to constitute a failure of the landing system, even though a landing may still be carried out. The manufacturer has recommended that component A should be overhauled or replaced at the end of its design life (R=0.98). Component A may be overhauled up to a maximum of four (4) times before it should be discarded and replaced by a new part. Component B cannot be overhauled and needs to have a hard-time replacement strategy applied. To overhaul or replace either component, the aircraft will be out of service for 1 day. The manufacturer is currently undertaking accelerated life-cycle testing with the airline to determine an optimum maintenance and replacement strategy for both Components A and B.

Attached in electronic form is a Microsoft Excel® spreadsheet containing time-to-failure data for the landing gear assembly. This source of this data is accelerated life-cycle testing. The samples of data contained in the spreadsheet may be considered partially complete and partially censored. The time-to-failure has been expressed in cycles, where one cycle represents a single landing.

This particular aircraft operator’s policy is to operate a critical component up to a time where it can be demonstrated that the component reliability falls below 98%. This is of course for those critical items that are not covered by aircraft maintenance regulations and air directives. The airline would be very keen to see a methodology developed that can assist it in identifying age-related failure rate profiles so that it can aim towards optimum maintenance policies.

You have been asked to develop a methodology and analyse the attached data in order to answer the following questions:

1. Using SAS® plot...