Cascade Mechanism (Framework)

The cascade mechanism resolves a structural challenge in multi-supplier frameworks that use direct award: how to choose which supplier receives each call-off without running a full mini-competition. By ranking suppliers at the framework award stage and then working down that ranking in sequence, the cascade preserves objectivity and avoids any appearance of favouritism in individual call-off decisions.

What is a Cascade Mechanism in a Framework?

A cascade mechanism is a type of direct award rule embedded in a multi-supplier framework. At the point of framework award, suppliers are ranked (typically by their evaluation score). When a call-off arises, the authority approaches the first-ranked supplier. If that supplier accepts, the call-off is awarded. If the first-ranked supplier declines (for reasons of capacity, conflict of interest, or the delivery timeline), the authority moves to the second-ranked supplier, and so on through the list.

The cascade is documented in the framework agreement and the original procurement documents, so all suppliers understand before they apply that their rank determines their priority for direct award call-offs. This transparency is what makes the cascade compliant with the non-discrimination requirements of Directive 2014/24/EU: each supplier's position is determined by objective evaluation at framework award, not by buyer preference at call-off stage.

Cascade rules vary. Some frameworks cascade on a per-call-off basis (each new requirement starts at rank 1). Others use a rolling or rotational cascade, where rank 1 who accepted one call-off moves to the bottom of the queue for the next, giving lower-ranked suppliers earlier access. The framework documents should specify which approach applies.

Why it matters for bidders

Your rank on a framework directly affects your expected call-off volume if the framework uses a cascade. A first-ranked supplier on a busy framework can receive a substantial proportion of all direct award call-offs. A fifth-ranked supplier on a five-supplier framework may receive very few unless the top four regularly decline.

When assessing whether to bid for a framework, consider how the cascade is structured. A rotational cascade distributes work more evenly; a strict top-down cascade concentrates revenue at the top. Your resource capacity and pricing strategy at framework bid stage should reflect where you realistically expect to land in the ranking.

Example

A housing association framework for planned maintenance admits five contractors ranked by evaluation score. The framework uses a simple cascade: each call-off is offered to Contractor A (rank 1) first. If Contractor A declines or fails to respond within five working days, the call-off moves to Contractor B (rank 2), and so on. In practice, Contractor A accepts most call-offs, and Contractors D and E receive only the work that the top three contractors declined.

Frequently Asked Questions

What triggers a move down the cascade?

The most common triggers are explicit declination by the higher-ranked supplier, failure to respond within the specified deadline, or a declared conflict of interest. Some frameworks also permit the authority to move down the cascade if the first-ranked supplier cannot meet the required delivery date or volume.

Is the cascade mechanism the same in all frameworks?

No. The cascade rules are set by the contracting authority when the framework is designed and documented in the procurement documents. They can vary significantly. Some frameworks use price re-competition (a form of mini-competition) rather than or in addition to cascade. Always read the framework's call-off procedure section carefully before bidding.

Can a supplier refuse a cascade call-off without penalty?

This depends on the framework terms. Some frameworks permit a limited number of refusals without consequence; others include provisions to suspend or remove a supplier who repeatedly declines call-offs. Blanket refusal of cascade call-offs is generally inconsistent with the spirit of framework membership and may result in removal.