Systems Glossary | Systems Guides

Asset: A physical or digital item that contributes to a system and may require inspection, maintenance or replacement.
Backlog: Identified work that has not yet been completed.
Bottleneck: A point whose limited capacity restricts the performance of the wider system.
Boundary: The practical line used to decide which components and dependencies are included in the analysis.
Capacity: The amount of flow, load, work or demand a system can handle under stated conditions.
Cascading failure: A failure that spreads through dependencies or overloads into other parts of a system.
Condition monitoring: Collecting observations or measurements to identify changes in asset condition.
Constraint: A limit imposed by equipment, process, time, staffing, rules, space or another dependency.
Control: A mechanism or decision rule that changes system behaviour.
Control loop: A repeated process of measurement, comparison, action and feedback.
Criticality: The relative importance of an asset, function or task based on the consequences of failure.
Dependency: Another asset, service, supplier, person or system required for the subject system to work.
Dwell time: Time spent stopped at a station, terminal, loading point or process stage.
Failure mode: A particular way that an asset, process or system can fail to perform its intended function.
Feedback: Information about results that influences later action or system behaviour.
Flow: Movement of people, water, energy, material, information or work through a system.
Headway: The time or distance between successive vehicles or service units.
Interlock: A condition that prevents an action unless required safety or operating conditions are satisfied.
Isolation: Separating an affected section so work or service restoration can proceed without involving the whole system.
Load: Demand placed on an energy, transport, equipment or operating system.
Maintenance window: A planned period when an asset or service can be taken out of normal operation for work.
Monitoring: Ongoing observation of system condition, performance or alarms.
Operating margin: Capacity or flexibility remaining before a system reaches an important limit.
Output: The result delivered by a system, such as treated water, transport service, energy or completed work.
Pressure zone: A part of a water-distribution system managed within a target pressure range.
Redundancy: Additional capacity, components or paths intended to preserve function when something fails.
Resilience: The ability to absorb disruption, continue essential function and recover.
Restoration: The organized process of returning a service or system to operation after an interruption.
Root cause analysis: A structured review of evidence and contributing conditions intended to reduce recurrence.
Service level: A stated expectation for availability, timing, quality or performance.
Single point of failure: One component or dependency whose failure can stop an essential function.
System: Connected elements operating within a boundary to produce an outcome.
System of systems: A larger result created through the interaction of several independently managed systems.
Throughput: The quantity of work, people, material or transactions completed in a period.
Work order: A record used to define, authorize, plan, execute and document maintenance work.
Cycle time: The elapsed time for a process or resource to complete one unit or cycle under stated conditions.
Kanban: A visual or electronic signal used to authorize replenishment or production.
Just in time: A production approach that replenishes work in response to demand while relying on stable processes and suppliers.
Overall equipment effectiveness: A combined measure based on availability, performance and quality using defined production-time rules.
Takt time: The production pace required to meet demand, calculated from available production time divided by required output.
Work in process: Material or units that have entered production but are not yet finished goods.
CNC: Computer numerical control used to execute programmed machine motion and process actions.
MES: A manufacturing execution system that connects production orders, status, materials, quality and shop-floor records.