Calculator

Spare Parts Inventory Savings Estimator

Estimate savings from spare parts controls across purchases and inventory carrying cost.

This tool is educational and operational. It is not legal, engineering, or financial advice.

Processed in-browser. Nothing is stored.

Inputs

Optional. Used in the memo output.

$

Use spare parts purchases for the last 12 months.

%

Estimated avoidable percent of in-scope purchases from spot buys, premium freight, and non-standard parts.

%

Conservative leakage rate after controls are installed.

$

Current on-hand inventory valuation for spare parts.

%

Percent of purchases and inventory covered by enforceable controls and governance.

%

Annual carrying cost percent for inventory (capital, storage, handling, obsolescence).

%

Estimated percent of in-scope inventory that is excess or obsolete today.

%

Conservative percent after cleanup and prevention controls.

%

Expected cash recovery percent on liquidated excess inventory.

$

Process, staffing, or tooling cost to implement and run controls.

Results

Enter inputs and click Generate.

Assumptions

  • This is an estimate. Validate using purchasing history, inventory on-hand valuation, and an excess and obsolete report.
  • Leakage rates are applied only to in-scope purchases.
  • Inventory reduction is estimated from excess and obsolete percent improvement applied to in-scope inventory value.
  • Carrying cost savings and purchase savings are different levers; keep assumptions conservative to avoid double counting.
  • Payback is implementation cost divided by monthly savings.

How to use

  1. Enter annual purchases, inventory value, and leakage assumptions using conservative inputs.
  2. Generate results and review the inventory reduction estimate for reasonableness.
  3. Copy or download the memo before sharing with Finance and operations leaders.
  4. Validate inputs with purchasing history and an excess and obsolete report.

What results mean

Estimated annual savings combines purchase leakage savings and reduced carrying costs.

Inventory value reduction is the in-scope excess and obsolete reduction based on your target percent.

One-time liquidation recovery reflects cash recovered from liquidating excess inventory.

Common pitfalls

  • Estimating leakage without reviewing spot buys and premium freight charges.
  • Using excess and obsolete percentages without an updated inventory report.
  • Ignoring recovery timelines when modeling liquidation cash flow.

Definitions

In-scope purchases are spare parts purchases covered by enforceable controls and governance.

Excess and obsolete percent is the share of inventory value likely to be liquidated or written down.

Carrying cost is the annual cost of holding inventory including capital, storage, and obsolescence.

Change log

v1.0 (2026-01): Latest release