EXIN LSSA Six Sigma Green Belt key terms

A measurable customer requirement translated from a vague voice-of-customer statement into a specific, verifiable characteristic that a process output must satisfy.

The structured collection of customer needs, expectations, and complaints gathered through interviews, surveys, and field data, used as input for defining project requirements.

A classification scheme that sorts product or service features into must-be, performance, and attractive categories according to how their presence or absence affects customer satisfaction.

A high-level process map showing Suppliers, Inputs, Process steps, Outputs, and Customers, used at project scoping to define boundaries and reveal where measurement should begin.

A formal document authorizing a Six Sigma project that states the business case, problem statement, goal, scope, team, milestones, and expected financial benefit.

A concise description of the observed gap between current and desired performance, including magnitude, location, and timing, written without stating a cause or a solution.

The process of identifying everyone affected by or able to influence a project, then assessing their interest, influence, and likely support to plan communication and engagement.

A project objective written to be Specific, Measurable, Achievable, Relevant, and Time-bound, so that success can be judged objectively at project closure.

A visual representation of the sequence of steps, decisions, and handoffs in a process, used to expose non-value-adding activity, rework loops, and measurement points.

A structured investigation using tools such as the fishbone diagram or 5 Whys to trace an observed effect back to the underlying system cause that, if removed, prevents recurrence.

A branching diagram that organizes candidate causes of a problem into categories such as people, machine, method, material, measurement, and environment to guide verification.

An iterative questioning technique that asks why a problem occurred repeatedly, each answer becoming the next question, until the actionable root cause is reached.

A statistical procedure that compares sample evidence against a stated null hypothesis, yielding a p-value used to decide whether an observed difference is likely real.

Type I error rejects a true null hypothesis (false alarm, probability alpha); Type II error fails to reject a false null hypothesis (missed effect, probability beta).

The probability of detecting a real effect of a given size, equal to one minus beta; it rises with larger samples, larger effects, and lower noise.

A test comparing means of three or more groups by partitioning total variation into between-group and within-group components and forming an F ratio.

A planned set of runs in which factors are deliberately varied together so that their individual and interaction effects on a response can be estimated efficiently.

A modeling technique that fits an equation relating one or more predictor variables to a continuous response, quantifying both the strength and form of the relationship.

A time-ordered plot of a statistic with center line and statistically derived limits, used to separate common-cause variation from special-cause signals.

The routine, inherent variation produced by the design of a stable process; reducing it requires changing the system rather than reacting to individual points.

Variation arising from an identifiable, non-routine event or assignable source, signaled by out-of-control patterns on a control chart and addressed by finding that source.

A lean tool that charts material and information flow across a whole value stream, including lead time and queue data, to locate waste and design a future-state flow.

Continuous, incremental improvement carried out by the people who do the work, often through short focused events that implement small changes quickly.

A workplace organization method whose five steps sort, set in order, shine, standardize, and sustain, reducing motion waste and making abnormal conditions immediately visible.

An error-proofing device or design feature that prevents a mistake from being made or makes an error immediately detectable before it reaches the customer.

A written, controlled instruction describing the approved method for performing a task, forming part of the control phase's effort to lock in improved performance.

A document listing each process characteristic, its specification, the measurement method, sample size and frequency, control method, and the reaction plan when a signal occurs.

A team-based risk assessment that scores each potential failure by severity, occurrence, and detection, producing a priority number that directs preventive action.

A visual diagram of the steps, information flows and delays that a product or service passes through, used to spot where value is added and where waste and waiting occur.

A picture of the sequence of steps in a process, showing who does what and where decisions are made, so the team shares one accurate view of how work really flows.