APMG LSS Yellow Belt key terms

Any activity or feature for which a customer is willing to pay because it changes a product or service in a way the customer cares about, delivered right the first time.

Any activity that consumes resources, time, or space but creates no value for the customer. Lean improvement work focuses on finding and removing it from processes.

A checklist of common non-value-adding activity types: defects, overproduction, waiting, non-utilised talent, transportation, inventory, motion, and extra processing. Teams use it to spot opportunities during process walks.

The complete sequence of activities, people, information, and material flows required to take a customer request from order to delivery, including both value-adding and non-value-adding steps.

A visual technique that charts the flow of material and information through a process, marking processing times and delays so the ratio of value-adding to non-value-adding time becomes visible.

The total elapsed clock time from when a customer request arrives until the finished output is delivered, including all waiting and queue time between steps.

The time a single unit actually spends being worked on as it passes through a process, excluding time spent waiting in queues between steps.

A relationship stating that average lead time equals average work in progress divided by average completion rate. It shows that reducing queues shortens delivery time without changing capacity.

The available production time divided by customer demand over the same period. It sets the pace a process must meet to satisfy demand without building excess inventory.

The ideal state in which work moves smoothly from step to step without batching, backflow, or queueing, so items are completed close to the rate customers need them.

A way of controlling work in which downstream steps signal an upstream step when they need more input, so production is triggered by actual consumption rather than by forecasts.

A visual signal, such as a card or empty container, that authorises an upstream step to produce or replenish a set quantity of items in a pull system.

The step in a process with the lowest capacity, which limits the output of the whole system and where queues tend to build up.

An improvement approach holding that every system has at least one limiting factor, and that gains come from identifying it, exploiting it, subordinating other steps to it, then elevating it.

The number of items that have entered a process but are not yet finished, including those being worked on and those waiting in queues.

A workplace organisation method with five steps: sort, set in order, shine, standardise, and sustain. It reduces motion and search waste and makes abnormal conditions easy to see.

A documented, agreed method for performing a task that captures the current best sequence, timing, and quality checks, and serves as the baseline for further improvement.

Using displays such as boards, labels, and colour coding so that anyone can see at a glance whether a process is on plan and where problems are occurring.

A visual or audible signal that alerts a team or leader that a problem has occurred and assistance is needed, allowing issues to be addressed before defects pass downstream.

A structured approach to making many small, incremental improvements, typically through short team-based events that focus on a specific process area.

The actual place where work is done and value is created. Improvement relies on observing and asking questions there rather than relying on reports or meeting rooms.

An ongoing organisational habit of finding, testing, and embedding small changes that improve quality, speed, or cost, rather than relying on occasional large projects.

A data-driven improvement methodology aimed at reducing variation and defects in processes, using statistical thinking and a structured project sequence to reach near-perfect output quality.

A five-phase improvement cycle: Define the problem and customer requirements, Measure current performance, Analyse causes, Improve the process, and Control the gains.

The first DMAIC phase, in which the team clarifies the problem, customer requirements, scope, goals, and business case, and secures agreement from the process owner.

The DMAIC phase in which the team maps the process, defines what to measure, validates the measurement system, and collects baseline data on current performance.

The DMAIC phase in which data and process knowledge are used to identify and verify the root causes of the problem, separating genuine causes from coincidence.

The DMAIC phase in which the team generates, selects, pilots, and implements changes that address verified root causes and then confirms the improvement is real.

The final DMAIC phase, which puts in place monitoring, standard work, and response plans so the improved performance is maintained after the project team disbands.

The collection and translation of customer needs, expectations, and feedback into specific, measurable requirements that a process must satisfy.

A measurable characteristic of a product or service that directly reflects what matters to the customer and is used to judge whether the process is performing acceptably.

The natural differences in process outputs over time. Understanding its size and causes lets teams decide whether a process is stable and capable of meeting requirements.

Normal, everyday variation built into the design of a stable process. It can only be reduced by changing the process itself, not by reacting to individual results.

Unusual variation arising from a specific, identifiable event or assignable factor outside the normal behaviour of the process, which should be investigated and eliminated.

The use of control charts to plot process data over time with statistically derived limits, so teams can distinguish normal variation from signals that something has changed.

A measure of process capability expressing how many standard deviations fit between the process average and the nearest specification limit, with higher values indicating fewer defects.

A comparison of the spread of a stable process's output against its specification limits, showing whether the process can consistently meet requirements.

The upper and lower boundaries of acceptable output set by customer requirements or design, as distinct from the control limits calculated from process data.

The measured level of current process performance, captured before changes are made, so that any improvement can later be compared against a fair starting point.

A study that checks whether the method used to collect data is accurate and consistent enough to be trusted before conclusions are drawn from that data.

The underlying reason a problem occurs which, if removed, prevents the problem from recurring. Addressing symptoms alone leaves the cause in place.

A structured investigation that moves beyond the visible symptom to find and verify the underlying conditions that produced a problem.

A simple questioning technique in which the team repeatedly asks why a problem occurred, typically about five times, to work from the symptom down to an actionable cause.

A cause-and-effect diagram that arranges possible causes of a problem into branches, often grouped as people, method, machine, material, measurement, and environment, to prompt broad thinking.

A bar chart of problem categories ordered by frequency, paired with a cumulative line, used to show that a small number of causes account for most of the effect.

A chart that groups numerical data into intervals and shows how many observations fall in each, revealing the shape, centre, and spread of a data set.

A diagram showing the steps, decision points, inputs, and outputs of a process, used to build shared understanding and to expose loops, handoffs, and unnecessary steps.

A process map arranged in horizontal or vertical lanes, one per role or department, that makes handoffs, ownership, and delays between functions easy to see.

A repeating improvement loop: plan a change and predict its effect, do it on a small scale, check the results against the prediction, then act to standardise or adjust.

A limited trial of a proposed change run before full implementation, used to test assumptions and gather evidence with contained risk.

A document that specifies what is monitored, how often, by whom, and what response is triggered when performance drifts, so improvements are sustained.

A short document authorising an improvement project that states the problem, goal, scope, team, milestones, and expected benefits, agreed with the sponsor.

The senior manager who authorises an improvement project, provides resources, removes organisational barriers, and is accountable for realising the intended benefits.

The person accountable for the ongoing performance and design of a process, who accepts improvements at handover and ensures they are maintained after the project ends.

A foundation-level improvement role. The holder understands core Lean and Six Sigma concepts, contributes to team projects, and applies basic tools in their own work area under guidance.

A trained improvement practitioner who leads smaller projects or supports larger ones part-time, applying DMAIC and basic statistics while continuing their normal role.

An experienced improvement practitioner, typically full-time, who leads complex cross-functional projects, coaches Green Belts, and applies advanced statistical methods.

Any person or group affected by, or able to influence, a process or improvement project, whose interests and concerns need to be identified and managed.

The recognised progression a team goes through as it matures, commonly described as forming, storming, norming, performing, and later adjourning.