Ship Universe Maritime Tool

Marine Spare Parts Inventory & Stockout Cost Tool

Estimate whether carrying a critical marine spare is economically justified by comparing annual inventory ownership cost with expected stockout exposure. Calculate lead-time demand, service level, expected shortage units, target stock, an economic stock level and the annual cost of downtime, emergency sourcing and obsolescence. Advanced mode screens an entire spare-parts portfolio.

Currency selector changes display only. No exchange-rate conversion is performed.
Lead-Time Risk
Demand rate, supplier lead time and probability that stock is insufficient
Inventory Economics
Capital carrying cost, storage burden, obsolescence and current inventory investment
Stockout Exposure
Downtime, emergency freight, rush premium and other shortage-related costs

Spare Part & Demand

Demand can represent expected failures, replacements or issues of one spare unit. Fractional annual demand is allowed for low-frequency failures.

$
units
Treated as units available to cover demand during replenishment and as carried inventory for this planning screen.
units/year
days
%
Probability that lead-time demand does not exceed the stocked units under the model.

Inventory Ownership Cost

%/year
%/year

Stockout Consequence

days/event
$ /day
%
$
% of part cost
$

Portfolio Economic Assumptions

Use Advanced mode for spares exposed to the same vessel or fleet downtime economics. Part-specific cost, demand, lead time, target service level and downtime duration remain editable by row.

$ /day
%
%/year
%/year
% of part cost

Spare Parts Portfolio

Annual demand may be fractional. Each demand unit is treated as one potential stockout event when unavailable. The economic stock level minimizes modeled annual holding + expected shortage cost.

Part Unit Cost Stock Demand/Yr Lead Days Target CSL % Downtime Days Expedite/Event Other/Event

Spare Parts Inventory Results

Single-spare stockout analysis

Enter spare data
Enter spare-part cost, expected demand and supplier lead time to estimate inventory ownership cost and stockout exposure.
Planning estimate only. Actual spare-parts requirements depend on equipment criticality, failure modes, installed redundancy, commonality, condition monitoring, class and statutory requirements, planned maintenance, repairability, supplier reliability, geographic trading pattern, customs, pooling arrangements, cannibalization options and contractual support. The Poisson demand model is a screening approximation and may not fit clustered failures, common-cause failures or highly variable supplier lead times. The tool assumes one spare unit per shortage event when valuing expected shortage frequency. Do not remove safety-critical, class-required or OEM-required spares solely because an economic model suggests lower inventory.
Results copied
By the ShipUniverse Editorial Team — About Us | Contact