Long-lead items are the packages whose manufacturing time is long enough to drive the project schedule: compressors, large transformers, switchgear, big valves or anything engineered to order. For these items the biggest risk is rarely the supplier’s factory. It is the date the RFQ goes out. If the enquiry is issued too late, expediting cannot recover the weeks that were lost before the order was placed.
This guide shows how to find the latest date to issue the RFQ for any long-lead item, using a simple backward calculation you can run in a spreadsheet.
What makes an item long-lead
There is no universal cut-off. Many project teams treat an item as long-lead when its manufacturing time takes up a large share of the time left before site needs it, or when it sits on the critical path. A practical test:
- Is the lead time measured in months rather than weeks?
- Is it engineered or built to order rather than taken from stock?
- Does it need factory inspection, testing or witness points before release?
- Will it ship by sea or need special transport?
- Would a late delivery stop the installation of other work?
Two or more yes answers usually justify tracking the item on its own long-lead list.
The two dates every long-lead item needs
Start from the required-on-site (ROS) date: the day the item must be at site to support installation. Then work backwards through every step that has to happen first.
Latest PO date = ROS date − transit − inspection and release − manufacturing lead time
Latest RFQ date = latest PO date − award − evaluation − bid period
Add the time your team needs to prepare the RFQ package (specifications, data sheets, commercial terms) and you also know when RFQ preparation must start.
A worked example
Fictional example: a gas compressor package is needed on site on Monday 10 April 2028.
| Step | Duration | Date |
|---|---|---|
| Required on site | Mon 10 Apr 2028 | |
| Transit (sea freight and customs) | 6 weeks | |
| Inspection and release | 2 weeks | |
| Manufacturing lead time | 52 weeks | |
| Latest PO date | 60 weeks before ROS | Mon 15 Feb 2027 |
| Award (negotiation and PO issue) | 3 weeks | |
| Technical and commercial evaluation | 4 weeks | |
| Bid period | 4 weeks | |
| Latest RFQ date | 11 weeks before the latest PO | Mon 30 Nov 2026 |
| Start RFQ preparation | 2 weeks before the RFQ | Mon 16 Nov 2026 |
On 21 October 2026, a site date almost 18 months away leaves just 40 days before the latest RFQ date. That is the point of the calculation: a comfortable-looking site date can hide a very short buying window.
Where the durations come from
The method is fixed; the durations are yours. Set them once per category and reuse them:
- Bid period: by package category, usually longer for engineered equipment than for bulk materials.
- Evaluation and award: include technical clarifications, commercial negotiation and internal approval at the right authority level.
- Manufacturing: use the supplier’s quoted lead time once you have it; before that, use recent quotations or past orders, not optimism.
- Inspection and release: depends on the inspection level, from document review only to witnessed factory tests.
- Transit: by shipping mode and route, including customs clearance.
If you want contingency, add it as an explicit line (for example, extra days for a new supplier) rather than padding every duration. Hidden padding makes it impossible to see where the time really goes.
Flag what needs attention
Once every package has its latest RFQ and PO dates, compare them with your planned dates:
- LATE: the latest date has already passed (negative float).
- AT RISK: the float is below your warning threshold, for example 30 days.
- OK: enough float remains.
Sort the long-lead list by float, worst first, and review it every week until each order is placed. After the PO is placed, the focus moves from buying to expediting: tracking drawings, inspections and shipping against the supplier’s schedule.
Common mistakes
- Leaving inspection and transit out of the calculation, which makes the PO date look later than it really is.
- Counting the bid period but forgetting evaluation, negotiation and approvals.
- Calculating once at kick-off and never updating when site dates move.
- Keeping the dates in one file and the package list in another, so nobody sees what is late.
Want to run this for your own packages? Our free Procurement Plan Template works back from each site date to the latest PO and RFQ dates for up to 10 packages and flags each one LATE, AT RISK or OK. For a full project, the Project Procurement Plan Builder adds room for 150 packages, a long-lead list sorted worst float first, a procurement timeline and a 12-section plan template in Word. Once the PO is placed, the Vendor Expediting Tracker takes over.