TEME key terms

The average operating time between consecutive failures of a repairable system, calculated by dividing total operating time by the number of failures observed. It estimates how long equipment typically runs before breaking down.

The average elapsed time needed to restore a failed system to working condition, including diagnosis, parts, and testing. It measures maintainability rather than reliability and directly limits how quickly service resumes.

The fraction of time a system is capable of performing its intended function, often expressed as uptime divided by total time. It combines how often failures occur with how quickly recovery happens.

A structured team exercise that lists the ways a product or process can fail, rates each by severity, occurrence, and detection, and prioritizes corrective action. It aims to prevent problems before they reach customers.

A deductive diagramming method that starts with an undesired top event and works downward through AND and OR logic gates to identify combinations of underlying causes. It supports quantitative probability estimates for complex systems.

A disciplined investigation that moves past symptoms to identify the underlying reason a problem occurred, then verifies that reason with evidence. Effective analyses produce corrective actions that prevent recurrence rather than quick fixes.

A simple questioning technique that repeatedly asks why a problem happened, typically about five times, to drill from surface symptoms toward a fundamental cause. It works best when answers are grounded in observed evidence.

A documented process for eliminating the cause of a detected nonconformity and for preventing similar problems from arising elsewhere. It includes investigation, action planning, implementation, and verification of effectiveness.

Any instance in which a product, process, or document fails to meet a specified requirement. Nonconformances must be recorded, evaluated for impact, and dispositioned through an approved route such as rework, concession, or rejection.

A documented, deliberate departure from an approved procedure or specification, authorized before or after the fact depending on urgency. Unlike an unplanned error, a deviation is assessed for risk and formally approved by responsible personnel.

A formal system for proposing, reviewing, approving, and recording modifications to products, processes, or systems before implementation. It ensures that impacts on safety, quality, and validated state are assessed and documented.

The documented act of demonstrating that a process, method, or system consistently produces results meeting predetermined acceptance criteria. It usually proceeds through installation, operational, and performance stages with defined protocols and records.

Confirmation, through objective evidence, that specified requirements have been fulfilled for a particular item or activity. It answers whether something was built correctly against its specification, as distinct from proving it suits its purpose.

The predefined, measurable conditions a product, process, or deliverable must satisfy to be approved. Clear criteria allow objective pass or fail decisions and should be agreed before testing or inspection begins.

The permitted range of variation around a specified nominal value for a dimension, property, or performance characteristic. Results inside the tolerance are acceptable; results outside it are treated as nonconforming.

A component or step whose failure alone halts the entire system or process. Identifying these vulnerabilities guides decisions about redundancy, spare parts, or backup procedures.

The practice of adding duplicate components, paths, or capabilities so that one failure does not stop the system. Redundancy can be active, with parallel units running together, or standby, with backups activated on demand.

Scheduled servicing, inspection, and part replacement performed before failure occurs, based on time, usage, or condition data. Done well, it reduces unplanned downtime and extends equipment life without excessive intervention.

Continuous or periodic measurement of parameters such as vibration, temperature, or pressure to detect early signs of deterioration. Trends trigger maintenance only when evidence indicates need, avoiding unnecessary scheduled teardowns.

Maintenance triggered by data-driven forecasts of remaining useful life rather than by fixed schedules. It uses sensor trends and models to intervene just before expected failure, balancing risk against maintenance cost.

Any person or group affected by, or able to affect, a project, decision, or outcome, including customers, employees, suppliers, regulators, and communities. Identifying them early shapes communication and requirement priorities.

A documented statement of a need or expectation that a product, service, or process must satisfy. Good requirements are specific, testable, and traceable to a source so that verification can later confirm fulfillment.

Uncontrolled expansion of project or product boundaries through small, often unapproved additions. Each change seems minor, but cumulatively they strain budgets, schedules, and quality unless routed through change control.

A hierarchical decomposition of the total scope of work into smaller, manageable deliverables and tasks. It provides the basis for estimating cost and duration and for assigning clear ownership.

The longest sequence of dependent tasks through a project network, which determines the shortest possible project duration. Any delay on this path delays the whole project unless it is compressed.

A significant, zero-duration point in a schedule marking completion of a major deliverable or phase. Milestones give stakeholders checkpoints for review and payment without representing actual work effort.

A tangible or intangible output produced to complete a project or process, such as a report, prototype, or approved design. Deliverables should be defined precisely enough that acceptance can be objectively judged.

A horizontal bar chart that plots tasks against a calendar timeline, showing start dates, durations, and overlaps. It helps teams visualize schedule dependencies and communicate progress to stakeholders.

A living document listing identified risks with their likelihood, impact, owner, and planned response. Regular review keeps it current and turns risk discussion into tracked action rather than a one-time exercise.

Action taken to reduce the probability or consequence of a risk before it occurs. Effective mitigation is assigned to an owner, scheduled, and reassessed, distinguishing it from merely accepting or transferring the risk.

A pre-prepared response activated if a specific risk materializes or a primary plan fails. It specifies triggers, responsibilities, and resources so the team can act quickly instead of improvising under pressure.

The amount and type of risk an organization is willing to accept in pursuit of its objectives. It guides decisions about which risks to treat and how much contingency to reserve.

A documented set of procedures for keeping essential operations running, or restoring them quickly, during and after a disruption. It covers people, facilities, systems, and suppliers and is tested periodically.

The subset of continuity planning focused on restoring information systems and data after an outage or catastrophe. It defines recovery time and recovery point objectives and relies on backups and alternate sites.

A formal contract between a provider and a customer defining expected service levels, such as response time or uptime, and remedies for shortfalls. It converts vague expectations into measurable commitments.

A quantifiable measure chosen to track progress toward a critical objective. Good KPIs are few, actionable, and tied to decisions, avoiding vanity metrics that look impressive but guide no action.

Comparing an organization's processes or performance against recognized standards or peer leaders to find improvement opportunities. The comparison must use consistent metrics to yield meaningful conclusions.

An ongoing effort to incrementally enhance products, services, and processes through small, repeated changes informed by data. It relies on employee involvement and measurement rather than one-off large projects.