Shop Order Lead Time Calculator (IFS Manufacturing)
Planned lead time in an ERP routing is only as good as its inputs. This calculator breaks a shop order into touch time and waiting so you can test whether the lead time your system assumes is credible.
Your numbers
This model assumes similar setup and run per operation.
Actual speed relative to standard.
Productive hours at the work center, per day.
Your results
Simplified single-resource model with no overlap between operations. Real scheduling depends on finite capacity, calendars and priorities.
Lead time vs order quantity
Sweeps Order quantity from 10 to 1000, holding your other inputs fixed.
Lead time accuracy review
Optional review comparing planned and actual lead times from your shop order history.
Optional. The tool and every export work without this. No spam.
How to use it
Enter the order quantity, the number of operations, and the setup and run time for a typical operation. Add run efficiency to reflect how fast people and machines actually work compared with standard. Then enter the available hours per working day at the work center, and the average queue and move times per operation. The result is total lead time in working days and the share of that time that is real work. Use the chart to see how larger lots lengthen lead time.
- Take queue times from actual order history
- Use one shift's productive hours unless you run more
- Average operations if routings differ greatly
- Compare the answer with the lead time on the item
The calculation
Run hours per operation equal quantity times run minutes per unit divided by 60, then divided by efficiency. Setup is added without an efficiency adjustment. Touch days are operations times hours per operation divided by available hours per day. Lead time is touch days plus operations times queue and move days. Touch share is touch days divided by lead time. The model assumes each operation waits for the previous one to finish completely, with no overlap or splitting.
Reading the result
In many job shops the touch share is in single digits to low double digits, meaning an order spends most of its life waiting. That finding changes where you act: shaving run time by five percent barely changes lead time, while cutting queues through load levelling or smaller releases changes it a lot. If the answer is far from the lead time held on the item, material planning is working from the wrong number and will release orders too early or too late.
Common mistakes
Using calendar days instead of working days mixes units. Treating standard run time as actual ignores efficiency loss, scrap and rework. Forgetting that large quantities lengthen the run, so one fixed lead time per item hides a quantity effect. Finally, queue time is not a constant: it grows sharply as work center utilization approaches full, so test a busy-period queue as well as an average one.
Frequently Asked Questions
Does this match IFS scheduling?
No, it is a simplified estimate for sense-checking. IFS scheduling can use finite capacity, calendars and overlap, which this model ignores. Use it to test whether stored lead times are reasonable, not to replace scheduling.
What is a good touch time share?
It varies by process. Highly flow-oriented lines show high shares, job shops often show low ones. The useful comparison is your own trend over time and against the share you would need to hit delivery promises.
How do I get queue time?
Compare order release or previous operation completion dates with the start of the next operation across a sample of recent shop orders. Average by work center, and separate busy and quiet periods.
Why does lead time grow with quantity?
Because run hours scale with units while setup is fixed. Larger orders amortize setup better per unit but occupy each work center longer, which is why lot sizing and lead time are linked.
Netray can help compare lead times stored in your ERP with what shop orders actually took, using your own order history. Ask if you would like to see how.
Related Tools
Takt Time and Machine Count Calculator
Convert monthly demand, shifts and breaks into takt time, then find how many machines are needed at your cycle time and OEE.
MES & Shop FloorOEE Calculator for Plex and MES Data
Compute overall equipment effectiveness and its three factors from a shift or day of production data, and see how rejects move the result.
Other ERPsQAD EOQ and Reorder Point Calculator
Calculate economic order quantity, safety stock and reorder point for an item, with a lead-time sweep, to set QAD item planning values on evidence.
More Other ERPs tools
See all- Infor VISUAL Work Order Status and Structure Reference
- Infor VISUAL Manufacturing Scheduling Checklist
- Infor XA (MAPICS) Period End Close Checklist
- Infor VISUAL Database Table Reference
- Infor XA (MAPICS) Application Module Reference
- IBM i Commands for Infor XA Administrators Reference
- Acumatica Generic Inquiry Design Template
- Acumatica Manufacturing Edition Setup Checklist
- Sage X3 Import Template Worksheet