Project Management

Lead Time

Also known as: Procurement Lead Time

The elapsed time from purchase order to material delivery. Critical for scheduling long-lead items like generators, switchgear, custom millwork.

Lead time is the calendar duration between issuing a purchase order and receiving the material on site. Standard commodities (drywall, framing lumber, paint) have lead times of days. Specialty items (custom millwork, structural steel, generators, switchgear, elevators, custom glazing) have lead times of weeks or months. Items procured during current supply chain disruptions can stretch even longer.

Lead time drives early procurement decisions on every project. Long-lead items must be identified during preconstruction, ordered at the earliest defensible point in design (often before drawings are 100% complete), and tracked weekly through fabrication and shipping. A switchgear lead time slipping from 16 to 24 weeks can push the entire project completion date out by 2 months. The procurement log and the project schedule must be reconciled at every monthly schedule update.

Frequently asked questions

What is a typical lead time for construction materials?+

Standard commodities (lumber, drywall, paint): days. Standard specialty (cabinets, doors, windows from stock): 4 to 8 weeks. Custom or made-to-order (millwork, structural steel, glazing): 8 to 16 weeks. Long-lead specialties (switchgear, generators, custom elevators, transformers): 20 to 60+ weeks.

How do contractors manage long lead times?+

Identify long-lead items during preconstruction, get owner approval to order at earliest defensible design milestone, issue PO with deposit, track fabrication weekly, confirm shipment dates 30 days out, and stage receiving so material arrives just before installation rather than weeks early.

What happens if a long-lead item slips?+

The project completion date slips by the same amount unless the missing item can be installed late or a substitution can be made. Contractors should notify the owner immediately when a critical lead-time issue surfaces; the longer the warning the more options the team has to mitigate.

Related terms

Long-Lead Item

Material or equipment with procurement time long enough to drive the schedule. Examples: switchgear, generators, custom millwork.

Submittal

A contractor-prepared document (shop drawing, product data, sample) submitted for design-team review before fabrication.

Baseline Schedule

The original approved project schedule used as the benchmark for measuring delay, acceleration, and progress.

Critical Path

The sequence of dependent tasks determining a project's minimum duration. Critical-path delays push the entire schedule.