Sixty-Eight Percent of Vessel Failures Can be Avoided
How can we further improve safe operability and maintainability in shipping and mobile offshore drilling units (MODUs)?
Traditional ship and MODU maintenance practices are centered around scheduled/time directed maintenance tasks in the most part with a common belief that the more equipment and components are maintained, the reliability and availability, plus longer useful life will be realized.
This assumption is wrong.
It is time to reconsider how we maintain our vessels? We are still implementing age-old maintenance strategies that believe the more maintenance carried out, the higher reliability is realized! Wrong. The maintenance periodicities established are arbitrary...without proper analytical justification.
Stop doing the job right...
Start doing the right job...
Paradoxically, the more maintenance we do, an increase in conditional probability of failure develops by introducing infant mortality...based on actuarial analyses and not arbitrarily derived. We can counter this by proper analytical engineering justification.
68 percent of marine vessel failures occur due to unnecessary maintenance, excessively invasive maintenance, incorrect installation and post testing installation, poor design and incorrect operation.
After a thirty year study into reliability engineering and in particular maintenance, repair and overhauls within the aviation industry on the then "complex" engineering systems back in the 1960's and 1970's, the results were startling in as much the long held belief of regular overhaul and maintenance was detrimental to the efficiency and functionality of the aircrafts.
Findings based on actuarial analyses showed 68 percent of failures were indeed random and more importantly, the realization that regular scheduled maintenance did actually not improve the reliability of equipment and components but rather increased the failure by introducing infant mortality into what were otherwise stable systems.
Today, this holds true and more so due to complexities of modern marine assets including equipment and control systems, the number of ways they can fail grows exponentially and proportionate to the variety and severity of failure consequences.
Shipping and marine support services to the oil and gas exploration and extraction industry are open to tough competition on a global scale with ever increasing demands placed upon safety and safety critical systems to avoid past fatal disasters such as Amoco Cadiz, Piper Alpha, Derbyshire, Petrobras 36, Deepwater Horizon and countless environmental marine pollution incidents with substantial costs to numerous stakeholders.
Constantly under scrutiny, maintenance costs have risen 10-15 percent per annum since 1979 with total spends estimated around $1 trillion. Operating costs can be substantially reduced by adopting a reliability-centered (RCM) maintenance strategy. The oil and gas industry is experiencing substantial cutbacks that affect the support services. By adopting this maintenance strategy it will realize the following benefits:
12 reasons to choose marine reliability-centered maintenance
• Greater safety integrity by engineering justification
• Environmental integrity (assists with MARPOL/SEEMP compliance)
• Improved operating performance
• Greater maintenance cost-effectiveness
• Reduction in OPEX
• Substantial reduction of needless maintenance tasks (40-70 percent)
• Longer useful life of expensive items
• A comprehensive database
• Greater motivation of individuals
• Better teamwork
• Improved operating procedures
• ISO 55000 compliant program
RCM is a program to achieve efficient scheduled maintenance for complex, non-complex equipment and local/global hull structures that is centered on achieving its inherent safety and reliability capabilities at minimal cost.
What RCM is not
1) A limited and selective process that picks and chooses the systems and/or the components to analyze such as that found in shortcut and streamlined versions of the process.
2) A process that selectively analyses only a few given systems or certain components that everyone, including the ship's cook, knows is a problem and that has a major effect on the operation of the vessel or facility when it fails.
3) A PM review of what is already being done on system ABC or component XYZ.
4) Converting time directed maintenance tasks into condition directed predictive maintenance tasks.
5) Performing an analysis on a piece part such as a bearing or a shaft for example.
6) Establishing PM templates for PM tasks. (Bloom, 2007)
Small Selection of Companies Already Using RCM
Kenneth Shakesby is Co-Founder and CEO at Relmar.
The opinions expressed herein are the author's and not necessarily those of The Maritime Executive.