What is the ideal maintenance strategy?
A look at both MoD and commercial
shipping best practice
Mr NA Tomlinson, IEng MIET MIMarEST
BMT Defence Services, UK
SYNOPSIS
With maintenance having a direct impact on reliability and availability it is a subject of great importance to
any ship owner, from commercial organisations to Governments. Drawing on first-hand experience of the
Royal Navy, Commercial Shipping and MoD, and the varying repair, maintenance and support strategies
within them it is possible to draw a number of comparisons. The goals of achieving lower maintenance costs,
higher safety standards, higher efficiency and lower environmental impact are common across the shipping
industry, as are their respective challenges. With vessel life extension projects more common than ever
before and the average age of the world fleet reported to be exceeding 20 years, adopting the right
maintenance strategy is critical. It is more often than not far easier to justify committing resource, time and
funding following a failure than it is to make the same investment to prevent that failure in the first place.
Successful maintenance and support strategies go beyond process and policy, and are highly dependent on
culture, resource and investment. By examining some of the common challenges faced by both the Royal
Navy and Merchant Navy, and the approaches adopted, this paper will present a blend of best practice in the
form a common set of ideals.
CAVEAT
The views and opinions in this paper are those of the author and not to be construed as the official view of BMT
Defence Services or the wider maritime enterprise.
INTRODUCTION
Maintenance strategies have a direct impact on whole ship safety, capability and availability. It is a subject of
great importance to any ship owner from commercial organisations to governments. The range of ship types in
operation today is vast. In the commercial domain they include bulk carriers, dry cargo ships, passenger and/or
vehicle ferries, cruise ships, container ships, offshore supply vessels and ocean going seismic survey vessels. In
the naval domain they include patrol vessels, frigates, corvettes, destroyers, assault ships and aircraft carriers,
amongst others. All ship types vary in size and complexity and whist there are some commonalities across most
ship types each ship is often best considered as a unique asset with its own characteristics. With different
methods of planning, contracting, directing and controlling ship maintenance, adopted across the marine industry
determining the ideal maintenance strategy is not a trivial exercise.
It is suggested that an ideal maintenance strategy maintains design intent, achieves availability targets, is
affordable, is flexible enough to deal with uncertainty, is sustainable and is underpinned by sound Learning
From Experience (LFE) & operational assumptions.
For some commercial ship operators, maintenance has historically been regarded as more of a financial burden
than as a mechanism for delivering a safe, reliable and high quality service. The benefits from developing and
applying a sound and systematic maintenance strategy have gained greater acceptance over the years resulting in
reductions of unnecessary downtime as well as increases in operational capability.
Authors’ Biography
Noel Tomlinson is currently a Senior Naval Engineer within BMT Defence Services providing engineering consultancy and
ship in service support across the defence and commercial sectors. He served in the Royal Navy in a range of engineering
appointments before, spending 7 years in commercial shipping performing a range of senior technical and project
management functions.
More recently ships are being recognised as major assets and with that, the application of asset management
tools and techniques are being more widely seen within ship management. This has been further aided by the
involvement of Lloyds register in the development of ISO 55001 – The international management standard for
Asset Management systems1.
Ship sustainment through life relies on the success of four interdependent strategies as depicted at Figure 1. This
paper focuses primarily on maintenance strategies, however due to their symbiotic nature one cannot be
discussed solely in isolation, so reference is made throughout to the other strategies.
Operating
Strategy
Maintenance
Strategy
Defect
Repair
Strategy
Upgrade /
Update
Strategy
Figure 1 Ship Sustainment Strategies
A maintenance strategy defines the means by which an organisation sets out to preserve the condition of the
vessel throughout its service life. Maintenance activities will include the survey & inspection, upkeep, repair
and replacement across the entire vessel incorporating equipment, systems and structure.
High operational demands and harsh environmental conditions will degrade a ships material state over time,
creating a gap between the design intent and the design state 2. An example of this relationship is captured in
Figure 2 which depicts the variation of performance and capability with time.
Figure 2 Variation in Design Performance with Time2
SHIP TYPE COMPARISONS
Modern surface combatants are often referred to as ‘Complex Warships’, however, it cannot be said that all
military ships are more complex than commercial ships.
With the exception of a few Warships (e.g. Queen Elizabeth Class Aircraft Carriers) the physical size and
weight of warships are much smaller than that of most commercial ships. Warships are outfitted with complex
sensors, weapons, communication and power and propulsion systems (often with higher levels of redundancy)
making them generally far more complex than most commercial ships. An increased number, complexity and
density of equipment and systems along with other added specialist features to achieve survivability within
Warships also reflect the greater scope of a typical Warship’s operating function, as opposed to the normal
limited less complex functionality of most commercial vessels. This being said there are a number of these
features that are equally found in some of the more complex commercial ships. Figure 3 shows the broad
spectrum of complexity for different ship types and postulates a “region of similarity” where the differences
between commercial and naval Warships may be much less than initially assumed.
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Figure 3 Illustrative Ship Type and Complexity Spectrum
SHARED STRATEGIC GOALS
The aim of most maintenance strategies is to ensure the asset remains capable, in a safe condition, and that
availability is maximised throughout its planned service life. A commercial ship is a high value asset with the
sole purpose of being available to support operations and/or generate revenue for the owner. For many
Commercial ships success is easy to define. Through utilisation ships generate profit for the business throughout
their service life, boosting both reputation and share price. A Warship on the other hand does not generate any
income. Its sole purpose is to be available to protect national interests at home and abroad, executing the
foreign and defence policies of government through the exercise of military effect and diplomatic/peacetime
activities in support of these objectives. Whilst accepting that these two different assets have very different
purposes, with respect to their maintenance there are a number of mutually coherent strategic goals.
The majority of these goals fall under two main shared objectives, namely (1) corporate/operational objectives
and (2) statutory objectives. Corporate objects are often expressed in platform targets such as availability or
punctuality that contribute to the wider strategic goals. The high level objectives detailed in the UK Defence
Equipment & Support (DE&S) Corporate plan 2014-20173 constitute these and are closely aligned to their
commercial equivalents.
Statutory objectives include classification society rules, International Maritime Organisation (IMO) regulations,
Maritime & Coastguard Agency (MCA), environmental and safety legislation and specific certification and or
contractual requirements. Together, corporate/operational and statutory objectives should drive the shape and
definition of any maintenance strategy used, with its successful delivery in turn enabling them to be met or even
exceeded.
Table I expands on these objectives and suggests other sub objectives that may be applicable to a representative
commercial ship and a Warship with an indication of their individual requirements and priority to illustrate
where deltas may exist.
Commercial Ship (RoRo)
Complex Warship
Safety
Be Safe -Compliance with ISM code,
ISPS, MARPOL, IMO, Class notation
H
Be Safe - Lloyds naval rules, Def Stans,
MARPOL, IMO
H
Maintain Design Intent
Ensure ship remains certified by class
authority & flag state
M
Maintain operational capability and design intent
through life
H
Financial
Optimise Profit
H
Be affordable
M
Reliability
Maintain Schedule and stay on task
M
Maximise operational capability
M
Availability
Maximise time ship is operational
H
Optimise fleet readiness
H
H
Sustainability
Maintain ship for predicted service life
L
Ensure ship is maintainable for 150% ship service
life
Adaptability
Be Flexible - enable the strategy to
evolve with the vessel
L
Ensure changes in operation and technologically
advancements are supported through life
M
Holistic
Enable a cross discipline / cross
departmental approach
M
Enable a cross branch / cross DLOD approach
M
Integrated
Enable effective Ship / Shore
integration
M
Ensure enterprise wide integration
H
Table I Strategic Objective Comparison
Whilst the stakeholders, drivers and consequence of failure may be different for commercial ships and
Warships, the strategic ambition to achieve performance, cost and time goals is shared. The ambition of lower
maintenance costs, higher safety standards, higher efficiency and lower environmental impact are common
across shipping as are the respective challenges preventing their achievement.
MAINTENANCE METHODOLOGIES
There are a number of methodologies relating to the maintenance of equipment and systems, which all fall into
one of three main groups; Preventive, Predictive & Reactive (Figure 4). The choice of method selected should
be specific to each equipment or system and based on a number of factors, including likelihood and more
importantly, impact of failure. The cost to mitigate a failure should be optimally balanced against the financial,
operational or safety cost of the failure occurring.
Maintenance Methods
Preventive
Planned
Maintenace
Predictive
Opportunistic
CBM
Reactive
Run to
destruction
Figure 4 Maintenance Methods
Run to failure
A blend of methodologies can enable the optimisation of maintenance scheduling and improve availability by
reducing downtime. The methodologies employed should however be subject to either continual monitoring or
periodic review to ensure that they remain optimised.
Over recent years the expectations associated with maintenance have grown significantly resulting in an
evolution from a reactive process to that of a predictive one (Figure 5).
Figure 5 Evolution of Maintenance Practices4
The current methodologies in use within shipping are very variable and often depend on ship type, age and
specification of components. Although Condition Based Monitoring (CBM) is becoming more common place
within commercial ships, maintenance generally still follows a schedule of planned maintenance, which may or
may not include elements of CBM.
The type and frequency of maintenance, and allocation of the appropriate spares holdings, should be carefully
considered as they will have a direct effect on resource requirements. Having the correct number of suitably
qualified and experienced personnel (SQEP) is a key consideration and in addition to the method driving the
requirement, limited SQEP may also drive the method selected. Commercial shipping has seen a trend in lean
manning over recent years which in turn has driven a change in maintenance practices. Although this is
happening more slowly within the Military, the trend is still present5. As technological developments emerge
and the complexity of condition monitoring systems on board ships advances, so may the requirement for more
highly competent and trained ships engineers.
Preventive Maintenance
Planned maintenance carried out at predetermined intervals, or according to OEM requirements, is the mainstay
and most frequently adopted method. The choice of frequency and level of maintenance is paramount to provide
a reduction in failure rates whilst not introducing unrequired and sometimes damaging checking or replacing of
components. Planned or preventive maintenance schedules on large complex ships can quickly grow to
unmanageable levels, resulting in a negative impact on morale, increased possibility that tasks will be missed
and reduction in task quality. It is essential that results and observations from preventive maintenance tasks are
recorded and monitored in order to assess their effectiveness and their frequency is adjusted as required. It is
highly likely that the level of maintenance will be directly related to component type, frequency of usage,
environmental factors and interfacing system variables. These in addition may also change during the lifetime of
the ship (e.g. largely during life extensions) resulting in the need for an ever adapting and evolving preventive
maintenance schedule. It is however, imperative that this is conducted in a controlled way across the ship and
fleet respectively. It is all too easy to lose control of when or why changes were made resulting in identical
pieces of equipment across a fleet all being maintained in significantly different ways.
Reliability Centered Maintenance (RCM), as adopted by the Royal Navy (RN) in 1984, has the potential to be
an effective way of reducing maintenance and focusing resource and priority according to likelihood and impact
of failure. It is now embraced across the enterprise and seen in the majority to be effective. However the RNs
decision to implement quite a revolutionary approach at the time and its inconsistent evolution since has led to
many issues. One of the difficulties experienced has been with the integration of the multiple Information
Systems (IS) required for the management and administration of RCM both ashore and onboard6. Also the lack
of policy at sea with regard to RCM and CBM approaches has in some cases led to an undermining of the
underpinning principles of the maintenance strategy itself.
The introduction of the platform safety case has ensured compliance of maintenance standards and has driven
new processes for optimising planned maintenance, predicated on the criticality of the systems and equipment
affected. In support of the Future Complex Warship Support strategy a maintenance optimisation project is
currently reviewing the RN RCM policy7. It is hoped that this ‘RN maintainer focused’ improvement
programme will lead to the re-balancing of the ships staff maintenance burden with their capacity, in turn
enabling more effective utilisation of their time.
Predictive Maintenance
Predictive maintenance is based on the actual equipment condition assessed by a combination of continual
monitoring, periodic measurement or testing activities, or integrating analysis. Complimentary to standard
preventive maintenance, it adds flexibility that historically was not present in structured methodologies.
Continual or periodic monitoring of vibration, temperature, pressure, current draw etc. is extensively utilised
across shipping in general to assess degradation and predict failure.
The reliance on either technically complex monitoring systems or the correct interpretation of vast amounts of
data has led to a number of initiatives not being successful. Commercial ships often have equipment and
components from many different manufactures and this has led, in a lot of cases to a variety of uncoordinated
monitoring systems. The success of fully integrated monitoring systems is often hampered by the ability to
either retrofit non OEM sensors or incorporate varying proprietary components into one system. CBM is a key
element of the Royal Navy’s RCM policy and combined with data from additional sources is utilised to further
optimise planned maintenance scheduling. The uptake of predictive maintenance methods across military
vessels in general appears to have happened earlier and been more integrated, than that of the wider maritime
sector.
Reactive Maintenance
Reactive maintenance is carried out following detection of an anomaly or failure and aimed at restoring normal
operating conditions. This approach must be based on the firm belief that the costs sustained for downtime and
repair in case of failure are lower than the investment required for preventive or predictive maintenance
programs. This strategy may be cost-effective until the point catastrophic faults occur and can be driven by high
levels of redundancy masking the impact of equipment failure.
Maintenance Summary
In a 2010 Chalmers University survey of maintenance strategy utilisation within the merchant fleet it was found
that only one out of the ten ship owners surveyed was introducing CBM, with the remaining opting for
preventive planned maintenance8. Although the introduction of risk based approaches has been quite slow
within commercial shipping in comparison to the Military, an ever-increasing application is being seen. The
Author has witnessed through his own experience the increasing application of familiar tools within defence
such as Failure Mode Effect and Criticality Analysis (FMECA), Reliability, Availability, Maintainability and
Safety studies (RAMS) and Fault Tree Analysis (FTA) being used within commercial vessel maintenance
management.
TIMING OF MAINTENANCE
The planning and execution of ship maintenance cycles including, dry docking intervals, major equipment
overhauls, certification renewals and survey/inspections is key. The majority of maintenance windows, whether
a few hours alongside or a major dry docking, have hard deadlines, often with consequential impacts for any
overruns. There is always a risk that trying to achieve too much or over minimising the down time required will
negatively affect the ships programme, often producing a knock on effect to several other ships.
Military vessels have historically had far longer refit periods than are common in commercial shipping, however
many countries have been working to optimise these, increasing the amount of time the ship is available for
operation. Optimisation for availability has however always been the key driver behind the majority of
commercial shipping maintenance cycles; with every day a ship is not operational costing money opposed to
generating it.
The optimum Maintenance, Upkeep and Operating Cycle (MUOC) will vary from class to class and even from
ship to ship due to a number of impacting factors. The ships construction, role, operating environment, average
length of voyage, age, support arrangements, size and skill of crew, etc. must all be taken into account and the
maintenance cycle refined accordingly.
Warships have several other factors that will drive their MUOC with training being a good example. The need
for rigorous training, exercising and testing of a ship and its ships company before it can be deployed is critical
in ensuring a warship is ready for any mission it may be required to conduct. This, however, is not a
consideration commercial shipping maintenance cycles have to account for, carrying out the majority of their
training either ashore or whilst in service.
STRATEGY DELIVERY
Breaking down maintenance strategy delivery and analysing the required tasks and interactions, there are four
interdependent functions that are critical to success:
1.
2.
3.
4.
Design & management;
Supply chain;
Empowered engineers;
Planning.
No one function alone can sustain a successful maintenance strategy, instead it requires an integrated approach,
with planning at the core. The strategic decisions that are made throughout the creation and delivery of a
maintenance strategy are critical, as they can impact on several, or all of the four elements, and all must be
planned with knowledge and understanding of the impact across the other functions. Figure 6 illustrates the
relationship between the four critical functions and the interdependencies between them.
DESIGN &
MANAGEMENT
PLANNING
EMPOWERED
ENGINEERS
SUPPLY CHAIN
Figure 6 - Maintenance Strategy Interdependencies Triangle
Design and Management
Engineering design and management will include the ship designers and shipyards through to the engineering
superintendents and chief engineers with functions including: strategy creation, specifying refit packages and
scheduling maintenance.
During any phase of ship design, entire new vessels and ship alterations, modifications and conversions, there
are a number of decisions which should be made with maintenance in mind. If the correct level of importance is
placed on maintaining the equipment, systems and ships through life at this early stage, a number of benefits can
be realised once in service.
Equipment selection and plant configurations will be assessed on a number of factors; however the correct
weighting on ease, cost and frequency of through life maintenance is not always applied. The decision to
continue maintaining or to replace/upgrade older or obsolete equipment and systems can be complex as there are
often many different factors driving the outcome. Often the cost associated with replacement of equipment or
systems is the main factor that drives the decision to continue maintaining existing ones often at the expense of
increased maintenance costs and reduced reliability. This is one area where the realistic estimation of through
life costs and a detailed obsolescence management/upgrade plan can make a significant difference. Anticipating
the need for upgrades/replacements far enough in advance allows for the need to be agreed and accepted, budget
to be set aside and the work to be planned with minimum effect on the ships programme. If estimated correctly
the replacement can be carried out before the point at which reliability reduces, impacting availability,
maintenance budgets, spares compliment and often overlooked, morale of the maintainers themselves.
Substituting different materials & methods in design, engineering, & manufacture can also result in further
benefit realisation with regard to through life maintenance costs. The minor adaptation of a design to improve
maintenance envelopes, access and removal routes can have a significant impact on the maintainability of
equipment and systems in service. There is an iterative process required, of designing with maintenance support
in mind and supporting the design through maintenance.
Empowered Engineers
Empowered engineers who are SQEP for the required task are critical to maintaining the physical condition of
the ship and therefore delivering a safe, reliable and available asset. The maintainers themselves, whether ships
staff, dockyard support, OEMs or specialist contractors, are one of the four critical functions. Responsible for
maintaining, repairing and upgrading/updating equipment and systems, they support and rely on both design and
management and the supply chain. Training and local supervision/management are key to creating and
preserving SQEP who can be empowered to make judgement calls as subject matter experts on the maintenance
of that equipment or system. The quality, suitability and condition of parts received is also best assessed by the
maintainers themselves and methods should be in place to allow this feedback to be received and acted upon by
both engineering management and the supply chain. The morale component of operational capability is highly
impacted both positively and negatively by maintenance strategies and the delivery of it is highly dependent on
the morale of the maintainers themselves.
Arguably ships by their nature of operating independently once at sea have created a culture where ships
engineers feel a sense of ownership of the equipment and systems on board and take great pride in maintaining
and rectifying defects without the need for external help. With the introduction of Contracting For Availability
(CFA) arrangements within the RN there is a risk of a negative shift from this traditional position, one still
common in commercial shipping. It is important to maintain the balance between outsourcing maintenance and
repair activities in order to preserve SQEP and ensure ships engineers remain empowered.
Supply Chain
The supply chain is responsible for sourcing, procuring, storing and delivering replacement parts, materials and
consumables items to the ship. This ongoing sustainment of the ship can only be achieved in coordination with
the other functions. Early engagement with the supply chain should be encouraged for all design changes or
significant management decisions as availability and cost of spares and support arrangements should be
considered. Commonality evaluations must also be undertaken, looking both from a vessel and fleet perspective
with regard to the impact on support arrangements, stores holding, training and ease of operation. It is essential
that the maintainers have a robust mechanism for identifying, ordering and receiving the spare parts they require
within the timescales required to support maintenance frequency. Often the supply chain is the first one to hear
of future obsolescence issues or unavailability of spares or support from Original Equipment Manufacturers
(OEMs) and suppliers.
Obsolescence management is key and should aim to plan in preventive resolutions rather than being forced to
take reactive ones. With the specific requirements of military components and equipment demanding a specialist
supply chain the importance of pre-emptive obsolescence management is greater than that of commercial
shipping who benefit from much wider procurement options.
COMMERCIAL CONSTRUCTS
Historically, commercial ships were often operated by the owner, with the majority of the roles and functions of
day to day running being carried out in house, supplemented to a lesser degree by specialist contractors or
services as needed directly contracted in.
For good reason complex Warships are often built and maintained by the countries indigenous shipyards and
dockyards. This provides benefit in terms of security of supply of infrastructure, resource and capability but can
reduce competitiveness, reduce the need to innovate and leave little scope for cost reduction.
The increasing reliance on OEMs and contractors to conduct maintenance is something that has been seen
across both commercial and military sectors. The wider use of CFA is a major contributor to this and has
brought a number of challenges including de-skilling of ship crews and reducing the sense of ownership or
empowerment felt by on-board engineers.
The Surface Ship Support Alliance was instigated by MoD as there was recognition that the traditional method
of contracting industry to maintain their vessels was no longer sustainable. One of the fundamental changes that
SSS alliance introduced was the concept of CFA, shifting the creation of refit specifications and maintenance
schedules from the customer to the contractor.
The RN now operate CFA arrangements for several classes, however in general the marine sector has been
much slower than other industries to adopt the concept of fixed price and availability contracts which may be
more common place in the civil aerospace environment9.
Examples of a typical traditional construct (Figure 7) and CFA construct (Figure 8) for a commercial ship
operator are shown. The ship owner or operator is shown in blue with the ship yard or contractors shown in red.
Suggested equivalent MoD functions have also been added in brackets, which although do not map exactly,
offer a representative illustration of comparable roles in in UK MoD.
Operations
(ODH)
Technical
(DE&S WSpt)
Ports /
Infrastructure
Marine &
Safety
Superintendant
(Plat Chf Eng)
Ships Staff
Water front
Engineers /
Riding gangs
Specialist
Contractors
OEM
Figure 7 Example of Traditional Commercial Construct
Shipyard
Operations
(ODH)
Technical(DE&
S WSpt)
CFA
Ports /
Infrastructure
Marine &
Safety
Superintendant
(Plat Chf Eng)
Water front
Engineers /
Riding gangs
Specialist
Contractors
OEM
Shipyard
Ships Staff
Figure 8 Example of CFA commercial Construct
The choice of commercial construct utilised will have a number of effects both positive and negative, Table II
compares a CFA arrangement with that of a traditional maintenance contracting method.
Traditional
Commercial
Construct
CFA Commercial
Construct
Advantages
Dis-Advantages
Full control over specification of work.
Financial risk lies with ship owner.
Transparency of cost per maintenance activity.
Ship owner defined strategy required.
Ships staff SQEP is maintained, engineers feel
empowered to diagnose and repair faults.
Ship owners SQEP level required to be maintained.
Transference of design management functions to
contractor.
Potentially more expensive method of contracting
maintenance.
Risk transferred to contractor.
Potential disconnect between ship owner and the technical
management of the ships.
Table II Commercial Construct Comparison
COMMON CHALLENGES
Keeping a fleet of ships in service and performing optimally over many years, brings with it a number of
considerable challenges, with a majority of them applicable to both naval and commercial ship operators/
owners. The most common of these challenges can be summarised as follows:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
Reduction in budgets – Maintenance budgets are often the first to suffer cuts with the true value of
maintenance only becoming apparent at a later date. This can lead to rectification costs that are
disproportionate to the original planned investment;
Un-realistic prediction of through life maintenance costs - Through life cost estimates are often
produced early in the design cycle based on immature data and are usually conservative, softening the
true through life cost to an unrealistic but palatable level;
Funding for reactive maintenance is often easier to justify – The replacement of equipment or systems
following catastrophic failure is often a ‘must’ opposed to a ‘should’ decision;
Optimisation - Calculating the minimum amount you need to spend on a ship to enable it to
successfully fulfil its function also carries risk, as often the only indication of the threshold is when you
have breached it.
Extension of designed operating life –Ship life extension projects are now common place, with the
average age of the world fleet reported to be exceeding 20 years 10. Gaining confidence that a life
extension requirement can be achieved with minimum impact on ship availability, and at a predictable
forecast cost is difficult;
High levels of equipment and system redundancy can breed a ‘fix on failure culture’ – Increased
redundancy and layers of protection can reduce the impact of failure, lowering the priority of planned
maintenance activities;
Obsolescence of equipment - The requirement to replace and upgrade systems and equipment through
life is increasing due to the nature and current speed of technological advances, specifically in
electronics, placing even more importance on pre-emptive obsolescence management;
Maintenance is not always fully understood or treated with the correct level of priority at board or
senior management level – This is often the case until an incident occurs;
Maintenance lacks a business culture - Strategies can be highly technically focused with minimal
business content or linkage to strategic goals;
Poor supervision or local management of maintenance tasks – Basic routine maintenance and upkeep
of the management system is often not carried out correctly;
Maintenance is isolated with little integration with other departments – Maintenance is often only seen
as an engineering function with little or no inputs from operators, supply chain or wider business;
Operational pressures result in low levels of planned maintenance – Lack of equipment downtime,
resource or spares often results in planned maintenance activities being deferred increasing the risk of
failure;
Preoccupation with advanced maintenance methods – A lot of reliance can be placed on hi-tech
methods which can fail due to a lack of basic practices.
MAINTENANCE STRATEGY IDEALS
Having looked at the higher strategic goals the maintenance strategy is required to contribute to, and the risks
and challenges which may prevent success, it is possible to produce a list of common attributes or ideals. These
are equally applicable to both naval and commercial marine sectors:
1.
2.
3.
4.
5.
6.
7.
8.
9.
Ensure Safe systems - Safety should be at the forefront of any maintenance strategy. The strategy
should seek to support the need to achieve greater personal safety and ensure all safety risks are As
Low As Reasonably Practicable (ALARP). Opportunities to reduce risk should be taken;
Maintain Design Intent - The maintenance strategy should always reflect the need to maintain design
intent;
Be Affordable - Fundamental to the sustainment of any strategy is its affordability;
Produce Reliability – Enabling engineering and management decisions to be strategic and scheduled
rather than reactive and disruptive;
Produce Availability - Redundancy, reliability, frequency and duration of maintenance periods and
efficiency of supply chain all contribute to producing whole ship availability;
Be Sustainable - Effective maintenance routines can enable a higher overall performance at lower unit
cost if sustained through service life;
Be Adaptable - The ability for a strategy to be adaptable through life and adapt to changes in operating
conditions is crucial;
Be Holistic - An effective maintenance strategy should be regarded of as a system of systems, a
holistic approach is key;
Be Integrated - Integral to the success of all the other ideals, without integration at the hub (Figure 9)
there is a significant risk of delivering one element at the detriment of one or more of the others.
NT
TE
IN
Y
AVAILABILITY
E
BL
NA
AI
ST
SU
ADAPTABLE
HO
LIS
TI
C
RE
LIA
BI
LIT
AFFORDABLE
GN
SI
DE
INTERGRATED
SAFE
Figure 9 – Maintenance Strategy Ideals Model
By exploring the similarities between commercial ships and naval Warships and the respective strategies put in
place to maintain them it has been possible to blend the accumulated best practice, in the form of the
Maintenance Strategy Ideals Model (Figure 9). For a wheel to run smoothly the hub must be directly in the
centre with all spokes balanced, this concept equally applies to the ideals depicted in the model. A successful
maintenance strategy must be driven forward through a unified approach that equally addresses all nine ideals.
Although equally applicable, the priority and specific requirements of these ideals will however remain
determined by the challenges and constraints unique to the ship and its operation.
CONCLUSION
The Royal Navy and Merchant Navy have hundreds of years of experience of maintaining ships. The influence
and best practice from other industries and professions has helped to shape the methodologies, philosophies and
theories currently in use.
It appears likely that the maritime industry will continue to look at the aviation industry for maintenance best
practice and that technologically advances will drive towards more complex data driven diagnostic methods
bringing new challenges to both military and commercial ships alike.
The strategic aims of a maintenance strategy and the challenges that can prevent it being successful are
comparable across both military and commercial vessels. Therefore it is asserted that the common set of
maintenance strategy ideals developed in this paper are equally relevant to both Commercial and Warship types.
Warships are highly complex and unique as a consequence of their role. The support enterprise that contributes
to maintaining them generally reflects this characteristic and is therefore sized and shaped to suit. However,
whilst Warships continue to be solely maintained by the defence enterprise it will remain difficult for
knowledge, experience and alternative practice to be ported across from commercial ship types.
They are examples of Commercial ship types that are similar in terms of complexity to Warships (e.g. Seismic
Survey vessels) and there are also similarities with respect to how they are operated and maintained. There are
also yards (e.g. in Northern Europe) that maintain both minor warships and offshore ship types. As a
consequence of this, the author is embarking on further work to determine if there are areas of read-across that
could provide insight and benefit to current thinking in relation to Warship maintenance and support.
Successful maintenance and support strategies go beyond process and policy and are highly dependent on
culture, resource, investment and the wider support enterprise. There is an ongoing challenge for ship owners
and operators across the marine industry to deliver effective and optimised maintenance strategies and the
sharing of best practice could be of benefit to all.
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