computer science

List of system quality attributes

List of system quality attributes is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand List of system quality attributes rather than just read about it. In short: Within systems engineering, quality attributes are realized non-functional requirements used to evaluate the performance of a system. These are sometimes named architecture characteristics, or "ilities" after the suffix many of the words share.

Key takeaways

List of system quality attributes belongs to computer science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect List of system quality attributes to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of List of system quality attributes from memory before moving on to harder problems.

Reference excerpt

Within systems engineering, quality attributes are realized non-functional requirements used to evaluate the performance of a system. These are sometimes named architecture characteristics, or "ilities" after the suffix many of the words share. They are usually architecturally significant requirements that require architects' attention. In software architecture, these attributes are known as "architectural characteristic" or non-functional requirements. Note that it's software architects' responsibility to match these attributes with business requirements and user requirements. Note that synchronous communication between software architectural components, entangles them and they must share the same architectural characteristics.

Quality attributes Notable quality attributes include:

Many of these quality attributes can also be applied to data quality.

Common subsets Together, reliability, availability, serviceability, usability and installability, are referred to as RASUI. Functionality, usability, reliability, performance and supportability are together referred to as FURPS in relation to software requirements. Agility in working software is an aggregation of seven architecturally sensitive attributes: debuggability, extensibility, portability, scalability, securability, testability and understandability. For databases reliability, availability, scalability and recoverability (RASR), is an important concept. Atomicity, consistency, isolation (sometimes integrity), durability (ACID) is a transaction metric. When dealing with safety-critical systems, the acronym reliability, availability, maintainability and safety (RAMS) is frequently used. Dependability is an aggregate of availability, reliability, safety, integrity and maintainability. Integrity depends on security and survivability. Security is a composite of confidentiality, integrity and availability. Security and dependability are often treated together.

See also Non-functional requirement Information quality ISO/IEC 9126 Software engineering—product quality Cognitive dimensions of notations Software quality

References

Further reading Erl, Thomas (2007). SOA: Principles of Service Design. Prentice Hall. ISBN 9780132344821. Gitzel, R.; Korthausa, A.; Schadera, M. (30 April 2007). "Using established Web Engineering knowledge in model-driven approaches". Science of Computer Programming. 66 (2): 105–124. doi:10.1016/j.scico.2006.09.001. Bass, Len; Clements, Paul C.; Kazman, Rick (2012). Software Architecture in Practice (3rd ed.). Addison-Wesley. ISBN 9780321815736.

Worked examples

Example 1 — a first encounter with List of system quality attributes

Start with the simplest possible case. Write down what List of system quality attributes claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to List of system quality attributes before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about List of system quality attributes ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of List of system quality attributes

In research: List of system quality attributes appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses List of system quality attributes in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: List of system quality attributes is common in secondary-school and first-year university syllabi. It links to neighbouring topics Software engineering terminology, Software quality, Software requirements, so understanding it makes those chapters shorter.
In everyday life: Look for List of system quality attributes outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study List of system quality attributes in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what List of system quality attributes means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain List of system quality attributes out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is List of system quality attributes in simple terms?

Why does List of system quality attributes matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study List of system quality attributes?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on List of system quality attributes.