Browsing by Author "Khan, S."
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item Open Access Studying the impact of intermittent variations using sensitivity analysis(British Institute of Non-destructive Testing, 2015-10-01) Khan, S.; Phillips, P.; Jennions, Ian K.Fault diagnostics focuses on the detection, identification and isolation of failures. However, this becomes challenging when investigating fault alarms that cannot be verified, diagnosed or even duplicated under standard manual inspection regimes. To improve system effectiveness, it is essential to investigate these instances, along with the effects of design parameters on system dynamic characteristics. Recent research has identified intermittent fault behaviour within components as one of the primary focuses for false alarms, and hence a direct consequence to the phenomenon of 'no fault found'. This paper examines the performance characteristics of an electronic system under intermittent component variations. Understanding occurrences in parameter deviations (and their impact) can help with understanding the requirements for improving system fault tolerance. It is shown that, in many cases of practical importance, components do not have the same sensitivity to intermittent variations and hence can be better suited for monitoring. The analysis provides extra information and guidance for the maintenance decision-making process in organisations on resource requirements.Item Open Access Towards standardisation of no fault found taxonomy(2012-11-06T00:00:00Z) Khan, S.; Phillips, P.; Hockley, Chris; Jennions, Ian K.; Roy, Shebab and Hockley, KhanThere is a phenomenon which exists in complex engineered systems, most notably those which are electrical or electronic which is the inability to diagnose faults reported during operation. This includes difficulties in detecting the same reported symptoms with standard testing, the inability to correctly localise the suspected fault and the failure to diagnose the problem which has resulted in maintenance work. However an inconsistent terminology is used in connection with this phenomenon within both scientific communities and industry. It has become evident that ambiguity, misuse and misunderstanding have directly compounded the issue. The purpose of this paper is to work towards standardisation of the taxonomy surrounding the phenomena popularly termed No Fault Found, Retest Okay, Cannot Duplicate or Fault Not Found amongst many others. This includes discussion on how consistent terminology is essential to the experts within organisation committees and, to the larger group of users, who do not have specialised knowledge of the field.