Customer Bank Build Stock Calculator
Before a tool transfer, plant move or planned shutdown, customers often ask suppliers to build a bank of finished parts. This calculator shows what that request costs in run hours, calendar time and carrying cost, before you accept it.
Your numbers
Hours not needed for normal production.
Your results
Excludes storage space cost, obsolescence risk and any customer funding of the bank.
Extra run hours vs bank days
Sweeps Bank requested from 0 to 40, holding your other inputs fixed.
Bank build planning in your ERP
Optional: talk through scheduling bank builds against orders and capacity in your ERP.
Optional. The tool and every export work without this. No spam.
How to use it
Enter the days of supply the customer wants and their daily demand from the latest release. Add the rated line speed and expected OEE, then the spare hours per day you can dedicate without hurting normal output. The result is the bank quantity and the time needed to produce it.
- Use the customer's latest release, not the nomination volume
- Spare hours are those left after normal production
- Run the chart to compare 5, 10 and 20 days
Formula
Bank quantity equals days of supply times daily demand. Effective good parts per hour equals rated rate times OEE. Extra hours equals bank quantity over that effective rate. Calendar days equals extra hours over spare hours per day. Carrying cost equals inventory value times annual rate times months held over twelve.
Reading the result
If calendar days to build exceed the time before the event, you need overtime, a weekend shift or a smaller bank. Compare the carrying cost with the expedite cost you avoid if the transfer slips. Agree who pays for the bank in writing, because it can tie up working capital for months and may become obsolete if the program changes.
Common mistakes
Planners often use 100 percent OEE or forget that parts built early age in storage and may need re-inspection or re-preservation. Another mistake is building the bank from a single material lot, which can hide traceability issues. Align bank labeling and lot control with the customer before starting.
Frequently Asked Questions
How many days of bank do customers ask for?
It varies widely with risk. Short transfers may ask for a week or two, while complex tooling moves may ask for several weeks. Use the customer's written requirement and your own risk assessment.
Who pays for the bank?
That is a commercial term. Some customers fund the inventory or buy it early, others expect the supplier to carry it. Settle payment and ownership before building to avoid disputes.
Does the bank change my OEE?
Not by itself, but extra running can raise utilization and reveal constraints. Use realistic OEE for the added hours and watch changeover and tool wear.
Can I use it for a seasonal build?
Yes. Treat the seasonal peak above normal output as the bank and set days of supply to the extra demand over the build window.
Netray can help model bank builds against open orders, material availability and capacity in your ERP so the plan is checked before the commitment is made.
Related Tools
Required OEE for OEM Volume Calculator
Back solve the OEE a cell needs to deliver a customer volume plus flex, and see the headroom or shortfall at your current OEE.
Supply Chain & InventoryReturnable Rack and Container Fleet Size Calculator
Calculate how many returnable racks your closed loop needs, the capital tied up and the yearly replacement budget, with a sweep on customer dwell days.
Supply Chain & InventoryPremium Freight Cost Per Part Calculator for Automotive Suppliers
Calculate the excess cost of premium freight events versus standard freight, per part and as a percent of revenue, with a what-if on event count.
Quality & InspectionRolled Throughput Yield and Rework Cost Calculator
Compute rolled throughput yield from the first time through yield of five steps, plus the starts required and the cost of rework.
More Supply Chain & Inventory tools
See all- Premium Freight Incident Log Worksheet
- Returnable Rack Pool Size Calculator
- Oracle Fusion Inventory Turns and Carrying Cost Calculator
- Distribution ERP Fill Rate Calculator
- Distributor Rebate Tracking Worksheet
- Branch Transfer Planning Worksheet
- Distributor Slow-Moving Inventory Review Worksheet
- Distributor Vendor Performance Scorecard Worksheet
- Distributor GMROI Calculator