Critical Spares Procurement, Lead Time, Inventory & Stockout Risk Tool

Criticality • Minimum Spares • Planned Consumption • Unplanned Demand • Lead Time • Supplier Reliability • Service Level • Stockout Probability • Downtime Exposure • Procurement Budget

Critical Spares Procurement, Lead Time, Inventory & Stockout Risk Tool

Convert onboard spare quantities into a risk-based procurement plan. Simple mode estimates the reorder quantity needed to protect a single critical spare through its procurement lead time. Advanced mode ranks an entire spares list using class/OEM/company minimums, planned maintenance demand, probabilistic unplanned demand, supplier reliability, MOQ/pack constraints, stockout downtime cost, holding cost and a finite procurement budget.

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Fast critical-spare screen: 10 inputs. The tool never invents a statutory minimum quantity. Enter the class/OEM/company minimum yourself. Random unplanned demand is modeled with a Poisson distribution over the entered procurement lead time; planned maintenance consumption is treated separately and deterministically.

InventoryMinimum + planned + risk buffer

SupplyLead-time stockout probability

EconomicsPurchase cash vs avoided exposure

Critical Spare Snapshot

Current onboard quantity Physical usable units available now.

Class / OEM / company minimum quantity Enter the applicable minimum, if any.

Planned consumption before replenishment arrives Units expected for planned maintenance during lead time.

Unplanned consumption / failure demand Expected spare-consuming events per year.

Procurement lead time days from approved order to usable onboard spare.

Target no-stockout service level Probability target for covering unplanned demand during lead time.

Unit purchase cost

Expected downtime if stockout occurs days of operational impact if the spare is unavailable when needed.

Vessel / operation loss per downtime day

Emergency freight / expediting cost Incremental cost per stockout event.

Fleet / Procurement Planning Basis

Procurement budget available now Budget allocator funds highest-priority recommended orders first.

Average late-delivery extension Additional days when a supplier misses the promised lead time.

Annual inventory carrying rate % of inventory value/year for capital, storage, obsolescence and handling.

Planning horizon months, used for annualized holding-cost display.

Critical Spares Register

Enter one row per spare. “Minimum qty” is the class/OEM/company requirement or internal minimum. “Supplier OTD” means on-time-delivery probability. The model adds the expected late-delivery extension to the nominal lead time for risk exposure, then rounds order quantity to MOQ and pack size.

Use	System / equipment	Spare / part	Criticality	On hand	Minimum qty	Planned use	Unplanned use / yr	Lead days	Supplier OTD %	Service target %	Unit cost	MOQ	Pack qty	Stockout downtime d	Emergency cost	Loss / day

Procurement / Inventory Verification Checks

Class / OEM minimum spare list reviewed Entered minimum quantities reflect applicable class recommendations, OEM manuals or company critical-spares policy. Physical onboard count reconciled Usable stock is reconciled with PMS/ERP quantity and damaged/quarantined items are excluded. Planned-maintenance demand included Upcoming overhauls, surveys and drydock work are reflected before calculating risk buffer. Supplier lead time / OTD validated Lead time reflects actual recent supplier/logistics performance, not only quoted factory days. Part interchangeability confirmed Superseded part numbers, maker approvals and sister-vessel compatibility are checked before relying on pooled inventory. Preservation / shelf-life risk checked Seals, elastomers, electronics, chemicals and long-stored components remain serviceable through the planning horizon. Emergency sourcing path reviewed Airfreight, riding squad, maker stock, regional warehouse and port-delivery constraints are understood. Budget exceptions escalated Any unfunded minimum-spare or high-stockout-risk item is explicitly escalated rather than hidden by the budget cap.

Planning boundary: this tool ranks inventory risk; it does not replace class, flag, OEM, SMS or company minimum-spares requirements. The stochastic calculation assumes independent spare-consuming events and a stable annual event rate. Common-cause failures, batch defects, simultaneous failures, supplier insolvency, customs disruption and vessel-specific redundancy can make actual risk materially different.

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