Stage-Gate Process

How the process is structured

Typically there is a stage for idea generation, followed by concept, business case, development, testing and validation, and launch. Each gate reviews the results of the previous stage against defined criteria, such as market attractiveness, technical feasibility and profitability. The outcome is Go, Kill, Hold or Recycle.

Why this matters for your decision

The gates in the early stages are cheap, the late ones expensive. Between business case and development, the largest budget is often committed: tooling, staff, supply contracts, tariff systems. At exactly this transition, the assessment of demand usually rests on desk research, concept tests and surveys.

In the classic model, the "testing and validation" stage comes after development: field trials, beta versions, trial production. By then the budget has already been spent. A behavioural test with realistic offer pages, by contrast, can be scheduled before the development gate, because it does not require a finished product. This moves part of the market validation forward, into a stage in which variants are still cheap to change.

Organisationally, this means anchoring a Behavioural Gate before the gate that releases the largest budget. The criteria there add evidence from observed behaviour to feasibility and profitability.

Example

A home appliance manufacturer has a business case for a water filter attachment with subscription cartridges. Before the development gate, the team tests two offer models in a Painted Door Test: buying the device with individual cartridges, or the device plus a cartridge subscription. Around 2,500 visitors per variant reach the offer page. The subscription achieves 2.2 percent measured purchase intent, the one-off purchase 2.7 percent. The gate releases development, and the business case is switched to the one-off purchase model.

How it differs

Agile development works in short iterations with continuous feedback and is combined with Stage-Gate in many companies. The Behavioural Gate is not a separate process, but a criterion that fits into an existing Stage-Gate process. The go/no-go decision is the outcome at a gate.

Limitations

Stage-Gate is often criticised as cumbersome when gates become mere formalities or demand too much documentation. More evidence then helps little if nobody specifies in advance which evidence counts for release. A behavioural test before the development gate measures demand for an offer, not technology, costs or repeat purchase. These criteria remain part of the gate.

Horizon delivers the behavioural data point for a gate from a Painted Door Test, in around four weeks from the question to the data analysis. The decision at the gate is made by the committee.