A stage gate process is a project management technique in which an initiative or project is divided into distinct stages, separated by decision points (known as gates). At each gate, continuation is decided by (typically) a manager, steering committee, or governance board. The decision is made on forecasts and information available at the time, including the business case, risk analysis, and availability of necessary resources (e.g., money, people with correct competencies).  Typically the aim of a Stage Gate process is to reduce uncertainty and obtain narrower ranges (more accurate estimates) as one progresses through each stage gate.

In oil and gas, a common set of five stage names is Appraise (or Identify), Select, Define, Execute, Operate. Some operators add a sixth stage , Abandon Appraise, Select and Define together are called  Front End Loading (FEL).  The decision gate between Define and Execute is normally called Final Investment Decision (FID) or “Sanction”.