The Vessel's Spares Parts Management ( within MPMS(CB))
Suppose the vessel does not have that spare part when needed, then the owner may be in big trouble.
However, it is impossible to keep an
extra vessel in the storeroom.
Vessels are trading worldwide, and it
is difficult to predict what might happen and when and do proper planning for the
delivery of necessary spare parts
Vessel spares are supplied in 4-6
months intervals for typical spares used throughout the year.
However, there is an analytical way to
minimize the expected costs if an unexpected breakdown occurs. In addition,
there is a way to identify critical spares that may affect the vessel earnings
if the spare part is not readily available onboard.
The process of that analytical way is following; keep in mind that using common sense to choose spares and machinery included in this process is paramount to the success of the process.
1st step is to calculate the
costs of whether or not to purchase and keep the critical spares.
2nd step is to estimate
downtime costs ( off-hire ), the failure frequency, and the lifetime of the
machinery where it will be used.
In case 1st and 2nd steps indicate that spare might be financially critical (high financial impact in case spare is not on board), then it is time to proceed
Step 3 Risk Assessment must be done keeping in mind redundancy of equipment, the criticality of equipment, experience-based of machinery maintenance history, condition-based monitoring etc
If all three steps indicate that a
spare part is critical or optimal for running maintenance and should be kept on
board, then that spare can be included in the planned maintenance and kept on
board
Combining these three results can
determine the criticality level l of spare and ensure that the best decision
has been made regarding that machinery and the vessel overall.
An Introduction to Planned Maintenance Storeroom Management
Planned Maintenance Storeroom
Management is the essential skill of any marine engineer in managing the
storage of spares required for normal vessel trading. Sometimes this has been compared to having a floating spare
parts store for the vessel
The maintenance items
inventory includes all the spare parts for machinery, tools, and
company-supplied consumable equipment such as safety glasses, overalls, etc.,
necessary for the vessel's normal day-to-day operation.
This category
excludes consumables, such as washers or bolts.
Planned Maintenance
Storeroom Management has three major goals:
- To have the spare that is
needed
- To supply that spare quickly
when it is needed
- To control the overall cost of delivering and keeping spares in stock
For example, suppose that a gasket on an emergency fire pump needs to be replaced about twice a year, but only when it "fails" (rather than on a pre-emptive maintenance schedule). That emergency fire pump will stop running until the gasket is replaced. There will be a significant delay in bringing it online if it is out of stock, even if the replacement can be purchased and delivered on board. If a replacement gasket is listed in the inventory but misplaced, there is still a delay as one or more engineers search for the item. Sometimes the response to this "crisis" is that a dozen gaskets are purchased, some stored near the emergency fire pump and more in the storeroom. That expense represents a 60 month supply; some gaskets will likely be misplaced in the coming years, completely wasting the purchase.
Setting up proper inventory
keeping procedures is essential in planned maintenance storeroom management.
The procedure must be simple and easy to follow.
The best solution is
to have that in an integrated software solution linked to approved PMS software
and purchasing software.( Danaos,PAL,BASS, NETPASS etc)
So the prerequisite
for proper spare parts management is to have a reliability-centred maintenance program (RCM) or machinery
planned maintenance system (MPMS) with condition-based monitoring (CB). The
advantage is that most maintenance is scheduled; therefore, the demand for many
maintenance spares are known in advance.
Ensure that the crew
members are given sufficient advance notice of the planned maintenance schedule
to pick up the spares and prepare maintenance "shopping carts" for
each machinery. Alternatively, to have enough notice ( including delivery time)
to order spare and have it on board just in time or before it is required.
This smoothes out the workload for the storeroom management and should lead to fewer errors.
One key recommendation is to consider a barcode computerized inventory management system for the maintenance supplies. This should integrate the purchasing, storage and stock-release functions, so the system tracks pending orders, expense authorizations, where items are stored, and to whom the items are released.
Ordering / Purchasing Guidelines for Planned
Maintenance Storeroom
This is usually where
engineers believe they do well and often do.
For improvement, it can be considered a kanban approach or some iteration of it: let demand-pull re-order process. While this usually is applied to parts and processes in manufacturing production, it can be applied to vessel maintenance parts, if appropriately planned in line with MPMS(CB)
The brief idea is to
order new stock (applicable to most consumables and select machinery spares)
when the remaining inventory drops to the point where the replacements will
arrive just before the system reports "out of stock" to the subsequent
request.
Basically, for select
items ( expensive consumables) purchasing system should have lead time included
in the description.
So when the item drops to min described stock or the rate of consumption reaches min level, the system alerts the user to place an order for the item so that item comes onboard when needed considering lead time.
This way, the risk is minimized, considering that this is being applied to the vessel.
Kanban requires a good
understanding of the lead for each item and the lead time between the order and
its delivery.
The benefit is that kanban minimizes inventory levels while maintaining enough supply to meet maintenance requirements on board.
Deciding Whether to Stock a Critical Spare Part
A financially-driven
decision on whether or not to stock a particular spare part compares the cost
of being out of stock against the cost of keeping a replacement part in
inventory. For example, once a machine breaks down and a replacement part is
required, there are two possibilities: the part is in stock, or it has to be
purchased. The extra cost for being out-of-stock is the hourly cost of
downtime, multiplied by the extra time required to purchase the item rather
than taking it out of inventory. On the other hand, the holding cost for having
the part in stock includes the interest on the pre-paid item, storage costs,
and depreciation if the part becomes obsolete before it is needed.
This calculation is essential
for expensive but critical spare parts. An informed decision requires knowing
the cost of downtime, how often the part must be replaced per year, and the
time it takes to purchase the new part.
It is overkill to run through this calculation for inexpensive or easily-stocked parts.
Stock-Keeping Guidelines
It is useless to have
a spare in stock if it is not found.
Again, most engineers
ensure that they have a system for keeping track of where spares are stored.
The best practice on
board or in any workplace is to keep the workplace tidy and organized; this is
especially important for spare past storage and inventory.
It puts the most frequently
used items nearest the point of use (in easy reach), the most-rarely used items
into storage areas and intermediate-use items in convenient places within sight
of the point of use.
Maintenance Storeroom Guidelines for Releasing
Stock
This is often the
downfall for engineers and other crewmembers. Engineers are undoubtedly rushing
to pick up spares and are not inclined to fill in the paperwork.
However, a lack of
control over stock withdrawal is similar to a self-serve store with no cash
register. Items that might be taken for personal use, such as safety glasses, solvents
or drill bits, might easily find their way to cabins. In addition, inventory
management and re-ordering are compromised even with most honest engineers
without some tracking system.
Worse yet, an
increase in the consumption of maintenance spares may be the symptom of a
significant problem with a machinery or maintenance process. Engineers might
overlook this if the problem builds slowly but could be visible as an increase
in usage even before it becomes an out-of-stock or over-spending issue.
How can the process
of taking spares from the planned maintenance storeroom be made quicker and more
accessible and with increased record-keeping accuracy?
The best
labour-saving approach is to use either a barcode scanner, QR code scanner or
RFID (Radio Frequency Identification) devices to
log spares as they are removed from inventory. This should, of course, be
integrated into the PMS
The best time-saver
to track which department (Deck /Engine) withdrew the spares is to use the
employee's computer-readable identification card. The withdrawal is then
charged to that employee's department budget.
Conclusion
A vessel's overall
performance relies heavily on how well its planned maintenance storerooms are
managed. The stock of spare parts may grow over time. When the machinery
for which they are intended is replaced, the newly obsolete spares might remain
on the shelves. Spares with a limited shelf life need to be replaced.
It can be difficult
to argue to reduce this inventory since an out-of-stock situation can stop the
vessel or reduce training capacity.
The requirement to
balance keeping the parts in inventory with the need to control spending is the
reason it is important to have a clear, rational, and well-understood policy.
The person in charge of the planned maintenance storeroom needs to know the
costs, the frequency of the need for specific critical, optimal, consumable and
expensive parts and the lead time required for purchasing them and delivering
them on board to keep that balance.
For more information and guidance contact us.
