Long lead items: why procurement sets the start-up date

One error recurs with great consistency on industrial and energy projects: the construction schedule is built forward from the start date and the procurement schedule follows behind it, "as required". As a result, items with long manufacturing cycles are ordered when their turn arrives in the construction schedule rather than when the start-up date demands.

What long lead items are

Long lead items are equipment and materials whose manufacturing and delivery cycle is comparable to the project duration, or exceeds any scope for compression. Typical examples: process lines, large transformers, hydro-mechanical equipment, switchgear, UPS units and chillers for data centres, overhead cranes, special valves and large vessels.

Their cycles run from 6 to 18 months from order: design to order, manufacture, factory acceptance testing, logistics and customs clearance.

Back-calculation: the only correct method

The order date cannot be set by budget availability or by the procurement queue. It is back-calculated from installation readiness:

• The date the equipment must be installed (from the construction schedule).
• Less installation duration and work front preparation.
• Less shipping, customs and site acceptance.
• Less factory acceptance testing and vendor acceptance.
• Less manufacturing duration.
• Less development and approval of made-to-order design documentation.
• Less tendering, bid evaluation and contract award.

The resulting date is the deadline for starting the procurement process. If it falls before design completion, part of the equipment must be ordered on preliminary data — normal practice that requires a management decision, not a reason to defer procurement.

Why accelerating construction does not help

Construction work compresses: crews can be added, second shifts introduced, additional fronts opened. Factory manufacture does not compress that way — production cycles and slots in a vendor's programme do not depend on what a client will pay for urgency.

That creates an asymmetry: construction slippage can be partly bought back with money, procurement slippage cannot. This is why project controls on industrial projects track the long-lead delivery programme as a separate critical path.

Construction slippage costs money. Long-lead procurement slippage costs time, and time cannot be bought.

Three practical checks

1. Does a formal long-lead register exist, with the lead time for each item and a calculated order date?
2. Are there items whose calculated order date has already passed? That answers the question of whether the start-up date is achievable.
3. Is manufacture tracked after award — production status, FAT dates, readiness to ship? An order placed does not mean equipment will arrive on time.

Where this belongs

The right place for long-lead work is Project Start-up, when the baseline and procurement plan are established. At that stage, identifying long-lead items and calculating order dates takes weeks and costs almost nothing. In month eight, the same work means revising the start-up date.