No Fault Found Problems in Asset Management

No Fault Found Problems in Asset Management

Samir Khan (Coventry University, UK)
Copyright: © 2017 |Pages: 20
DOI: 10.4018/978-1-5225-0651-5.ch020
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Within aerospace and defence sectors, maintaining asset availability during operational service has become more important than quality of service throughout the system life cycle. This requires organisations to establish cost effective strategies to manage uncertainties within their value led services e.g. maintenance activities. In large organizations, it is not always apparent whose decision affects the outcome the most. Often, accountability moves away from the designated organization personnel in unforeseen ways, and depending on the decisions of individual decision makers, the structure of the organization, or unregulated operating procedures may change. This can have far more effect on the overall reliability leading to inadequate troubleshooting, repeated down-time and reduced availability. This chapter focuses on discussing the No Fault Found problems in aviation and highlights the drivers that influence its decision making process. It further articulates the contents of tacit knowledge and discusses the knowledge gaps with current management policies.
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A set of businesses whose activities can be classified as the operation, maintenance, service, manufacturing, etc, can be regarded as an industrial network (Low, 1997). They can be analysed in terms of the patterns of their actors, activity links and resource links. A supply chain is a good example of such a network where numerous interactions exist – which can group together suppliers, system environment, services and customers, all into a cohesive entity. These actors (belonging to the entity) within the supply chain, coordinate their activities and collaborate together in order to improve the efficiency of the whole system in general. However, as technological complexity increases, the likelihood of system interruptions at any point in the network increases as well (Singh, 1997). This indicates that modern technology is strongly reliant on the correct functioning of these technical assets within the overall network. This reliance has made it susceptible to their failure. Any interruption – due to component degradation or incorrect use, is of concern not just to the operator (the user of the system) but also to everyone involved i.e. the manufacturers, suppliers and maintainers of the equipment. This can have adverse effects on safety, availability, and reputation; directly reducing the cost-effectiveness of all elements of the supply chain (Khan et al, 2015).

Interruptions can occur in different forms. Gradual degradation, given the time taken to source and fit a new electronic component, is rather trivial. However, a component breaking during operation is more alarming, as it impedes the ability of the system to perform its function until the component is replaced. Another form of interruption (in the same category) is that of reported faults where the root-cause of the problem cannot be diagnosed. In these situations, a suspected component is swapped, only for it to be found that the fault has not gone away. Furthermore, when the removed component is makes its way through the supply chain to the supplier to be tested (for functionality), it is found to be functioning as expected. This phenomenon has been given the name “No Fault Found (NFF)” and is the subject of this chapter.

Successful maintenance activities require one hundred per cent effort to ensure customer’s expectations with service reliability and availability (Zeithaml et al, 1990). However, the occurrence of faults where the root cause cannot be determined, usually described as NFF can be a disruptive mechanism on realizing customer demands. As new technology and innovative designs diffuse within system service, together with an aggressive operating environment, a variety of unpredicted failure modes can manifest themselves. These faults are often unanticipated by design engineers and the traditional diagnostic systems may not be able to diagnose them. As the aerospace and railway industries continuously strive to improve their performance, by delivering more reliable vehicles, with a higher availability, operational pressures reduce the time available for diagnostic investigations. This results in on-speculative replacements and hence higher levels of NFF (James et al, 2002).

The implications are therefore, operationally and economically detrimental – with erroneous diagnoses procedures, maintenance activities can penalise organisations in terms of lost man-hour costs, machine downtime and unavailability of system assets. It can further damages reputation and business relations with anyone within the component supply chain. Some studies have even suggested that equipment having an in service life of around 20 years, the operating and service/maintenance activities accounts for about 60 – 80 per cent of the total whole life cycle cost of the system (Pickthall, 2014). Over the years, organisations have established strategies to manage uncertainties, like NFF, within their maintenance activities. Most often, information processing and decision aiding systems are employed but, it is not always apparent whose decision affects the outcome the most and hence accountability moves away from the designated people in unforeseen ways1.

This chapter focuses on the aerospace industry’s decision making ability with regards to maintenance activities, in particular with NFF events. It examines accounts reported by maintenance professionals in order to articulate the underlying dynamics within organisations. The following sections with help the reader with:

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