Components and Processes That Keep Systems Safe and Efficient

Any two: brakes, seat belts, airbags, headlights and signals, mirrors, windshield wipers, horn.

A control component. It turns the system on and off.

Air flows through it easily, so the blower fan uses less energy to move warm air. A clogged filter makes the system work harder.

A process in an emergency department that sorts patients by how urgently they need care, so the sickest people are treated first.

Regular inspection and maintenance by trained elevating devices mechanics (and safety checks overseen by the TSSA in Ontario).

It is a safety feature. It keeps hands, hair and clothing away from moving parts so people are not hurt.

Examples: self-checkouts or more open lanes at busy times, an organized layout, conveyor belts at checkouts, stock tracking so shelves are refilled before running out.

Smoke (a sign of fire).

A control component.

Regular care, cleaning, adjusting and repair that keeps a system working well.

A fire drill (or lockdown practice, hold-and-secure practice, crossing guards, a visitor sign-in rule).

Oil reduces friction, so less energy is wasted and the chain lasts longer (less rust and wear).

Control: the dials or touch pad. Process: the burner or element that heats. Safety: for example an indicator light that shows a surface is still hot, or a control lock that stops young children from turning it on. Efficiency: matching the pot to the burner size, an insulated oven, a lid on the pot (a process that saves energy).

If too much current flows (for example, too many devices plugged into one circuit), the breaker switches off the circuit automatically. This stops wires from overheating and starting a fire.

Worn or loose parts might not be found. The machine could break down (stopping production and wasting time) or injure workers. Skipping maintenance usually costs more in the end.

A checklist is a safety process. It makes sure important steps (right patient, right procedure, all tools counted) are never forgotten, even when people are busy or tired.

Example: the speedometer shows the driver the speed so they can keep within the limit; a low tire pressure warning light tells the driver a tire needs air; backup sensors beep when an object is close. Each sends information about the system back to the driver so they can adjust.

Example for a chairlift: input: electrical energy; process: a motor turns a large wheel that pulls the cable; output: skiers carried up the hill; control: the operator's control panel; safety: safety bars, an emergency stop, attendants who slow the lift for young riders; efficiency: chairs that carry several people at once and a cable loop that keeps moving.

A sign is only one information component. A safe system also needs physical safety features (railings, smooth joints, a deep enough splash pool), people (trained lifeguards who control when riders go), processes (daily inspection and maintenance, staff training) and feedback (reports of injuries or near-misses used to improve the slide).

Safety features can add weight, cost, time or energy use (e.g. a heavier car body, extra checks before an elevator moves, airport security lines). Designers look for features that give large safety benefits with small costs, use new materials (light but strong), and test designs. Safety comes first when lives are at risk, so some loss of efficiency is accepted.