Disruption Claims under FIDIC: how to evaluate productivity loss

A disruption claim is a claim for loss of productivity. It is not the same as a delay claim. A contractor may lose money through inefficient working even if the formal completion date does not move.

This is why disruption claims often fail: teams try to prove them as EOT or prolongation claims. The logic is different.

Delay vs disruption

Delay asks whether completion or the critical path changed.

Disruption asks why a specific operation became less efficient than it should have been, and what direct cost that caused.

Example: concrete works continue broadly on programme, but late drawings, restricted access and repeated resequencing mean the crew places fewer cubic metres per shift. Completion may not move, but labour and equipment cost increases.

That is not necessarily EOT. It may be productivity loss.

What a disruption claim must prove

The minimum proof usually covers:

1. Normal or expected productivity.
2. A compensable disruptive event.
3. Actual loss of productivity.
4. Causal link between the event and the loss.
5. Calculation of additional direct cost.

It is not enough to say, “we spent more man-hours than planned”. The claim must explain why the overrun resulted from a specific disruptive event, not from the contractor’s own inefficiency.

Why Measured Mile is valued

Measured Mile compares productivity in an affected area or period with comparable unaffected work on the same project.

Its strength is that it reduces the debate about tender norms. Instead of arguing whether the original estimate was realistic, the parties compare actual performance by the same contractor under comparable conditions.

The method works only if:

• there is enough data for affected and unaffected periods;
• the works are genuinely comparable;
• scope, crew composition, location, weather and access do not distort the comparison;
• other causes of productivity loss are excluded.

If a clean measured mile is not available, a modified approach may be used, but it must be explained transparently.

Records needed

Productivity claims need production data, not only letters:

• daily reports by crew and activity;
• manpower and equipment logs;
• quantities installed per shift, day or week;
• location-based progress records;
• photos linked to work area and activity;
• RFI and design response logs;
• access permits, handover dates and interface registers;
• records of stacking of trades, resequencing and waiting time;
• cost records for labour, plant and subcontractors.

If records exist only at the level of general project progress, productivity loss is very hard to prove.

Total cost and modified total cost

The total cost approach compares actual cost with tender cost and claims the difference. It is convenient, but usually weak: it mixes pricing errors, contractor inefficiency, market conditions, weather, scope changes and Employer events.

Modified total cost may be more defensible if the contractor proves the reasonableness of the estimate, excludes its own errors, separates unrelated events and explains why a more precise method is not possible.

As a starting point, event-by-event analysis or Measured Mile is usually stronger.

Connection with EOT and prolongation

Disruption can exist alongside EOT, but they are different heads of claim.

• EOT protects against delay damages and may support prolongation cost.
• Disruption compensates loss of efficiency in specific works.
• Prolongation cost concerns extended presence on the project, not lower output per resource.

That is why disruption should be separated from EOT analysis and from prolongation costs.

FAQ

Must the disruptive event be on the critical path?

Not necessarily. Productivity loss can be a financial claim without impact on completion. Causation and quantum still need proof.

Can tender productivity be used?

It can, but it is more vulnerable than Measured Mile. Tender norms may be attacked as optimistic or commercially understated.

What if records are limited?

Choose a method honestly based on available records and disclose limitations. A narrower, well-proved claim is often better than a broad weak claim.

Bridge Consult helps contractors and employers separate disruption from delay, select productivity loss methods and test evidential sufficiency before submission to the Engineer or DAAB.

Sources and further reading

• Society of Construction Law, Delay and Disruption Protocol, 2nd Edition, February 2017.
• HKA, The distinction between disruption and prolongation claims, 2021.
• FIDIC, Conditions of Contract for Construction, 2017 edition.
• See also: Claims substantiation and EOT and delay analysis.