Reliability vs. Dependability — What's the Difference?

Consistency over time.

Incorporates reliability.

Performance-based.

Broad trustworthiness.

Improves with quality control.

Safety and availability.

Quantifiable through testing.

Maintainability is key.

Focus on avoiding failures.

Reflects overall system integrity.

Capable of being relied on; dependable

In systems engineering, dependability is a measure of a system's availability, reliability, and its maintainability, and maintenance support performance, and, in some cases, other characteristics such as durability, safety and security. In software engineering, dependability is the ability to provide services that can be trusted within a time-period.

Yielding the same or compatible results in different clinical experiments or statistical trials.

Trustworthy.

The quality of being reliable, dependable, or trustworthy.

The characteristic of being dependable; the ability to be depended upon.

(education) the ability to measure the same thing consistently (of a measurement indicating the degree to which the measure is consistent); that is, repeated measurements would give the same result (See also validity).

The trait of being dependable or reliable.

(engineering) measurable time of work before failure

The trait of being dependable or reliable

The state or quality of being reliable; reliableness.

The trait of being dependable or reliable

Yes, a system can perform consistently (reliable) but might not be considered dependable if it lacks in safety, availability, or maintainability.

Reliability focuses on consistent performance, while dependability includes reliability along with safety, availability, and maintainability.

Reliability is often measured using statistical methods to predict failure rates and performance consistency.

Dependability ensures that a system is not only reliable but also safe, available, and maintainable, which is crucial for user trust and satisfaction.

Safety is a critical component of dependability, ensuring that a system does not cause harm to users or the environment.

Reliability is a component of dependability; the importance depends on the context, but dependability offers a more comprehensive view of system trustworthiness.

Maintainability, the ease with which a system can be repaired or maintained, is a key aspect of dependability, ensuring that the system remains functional over time.

Availability ensures that a system is accessible and functional when needed, contributing to its overall trustworthiness.

Improving safety, availability, or maintainability can increase dependability without directly affecting reliability.

A dependable product could be a car that is not only reliable in starting and running but also safe in emergencies and easy to repair.

Engineers ensure dependability by designing for reliability, safety, availability, and maintainability, along with rigorous testing and quality assurance.

Consumer expectations can drive improvements in both reliability and dependability as businesses strive to meet or exceed these expectations to gain trust and satisfaction.

Yes, there are various standards and methodologies for measuring reliability and dependability across different industries.

Yes, software systems can be designed to be both reliable, in terms of consistent performance, and dependable, through attention to safety, availability, and maintainability.

Improving reliability typically contributes to increased dependability, but dependability also requires attention to safety, availability, and maintainability.