What Does Quality Mean? Operational meanings: CISC 323: Intro to - PDF document

✛ ✂ ✛ ✚ ✂ ✞ ☎ ✄ ✄ ✜ ✘ ✚ ✞ ✛ ✚ ✙ ✙ ✙ ✢ ✣ ✘ ✁ ✡ ✠ ☎ ✞ ✄ ✄ ✂ ✿ ✛ ✂ ✚ ✒ ✔ ✒ ✛ ✞ ✠ ✘ ✗ ☛ ✛ ✄ ✂ ✁ ✾ � ✘ ✣ ✒ ✢ ✒ ✔ ✒ ✛ ✙ ✠ ✛ ✣ ✄ ☎ ✖ ✏ ☞ ☞ ✕ ✒ ✔ ✛ ✑ ✎ ✠ ✍ ✌ ☞ ✠ ✞ ☛ ✄ ✡ ✄ ✞ ✢ ❀ ✠ ☎ ✒ ✄ ✄ ✂ ✁ ✙ ✄ ✚ ✛ ✞ ✚ ✜ ✂ ✄ ✄ ✡ ☛ ✔ ✒ ✘ ✘ ✗ ✖ ☞ ☞ ✕ ✔ ✞ ✔ ✑ ✏ ✎ ✍ ✌ ☞ ✠ ✒ ✒ ✠ ✕ ✙ ✘ ✘ ✗ ✖ ☞ ☞ ✒ ✙ ✔ ☎ ✑ ✏ ✎ ✍ ✌ ☞ ✙ ✚ ✛ ✚ ✞ ✠ ✛ ✣ ✘ ✢ ✛ ✂ ✛ ✞ ☎ ✄ ✄ ✂ ✜ ✚ ✞ ✘ ✞ ✛ ✔ ✡ ✠ ☎ ✄ ✄ ✂ ✁ ✒ ☛ ✔ ✒ ✛ ✞ ✠ ✛ ✣ ✘ ✄ ✞ ✛ ☞ ✚ ✙ ✙ ✘ ✘ ✗ ✖ ☞ ✕ ✠ ✒ ✔ ✑ ✏ ✎ ✍ ✌ ☞ ✢ ✚ ✛ ✞ ✑ ✏ ✎ ✍ ✌ ☞ ✠ ☛ ✒ ✄ ✡ ✠ ☎ ✄ ✄ ✂ ✁ ✔ ✕ ✂ ✛ ✞ ☎ ✄ ✄ ✂ ✜ ✚ ✞ ✚ ☞ ✙ ✙ ✙ ✘ ✘ ✗ ✖ ☞ ✚ ✙ ✞ ☞ ✔ ✠ ✑ ✏ ✎ ✍ ✌ ✠ ✕ ✞ ☛ ✄ ✡ ✠ ☎ ✚ ✄ ✒ ☞ ✂ ✞ ✂ ✞ ☎ ✄ ✄ ✂ ✜ ✚ ✛ ☞ ✚ ✙ ✙ ✙ ✘ ✘ ✗ ✖ ✄ ✞ ✁ ✚ ✠ ✛ ✣ ✘ ✢ ✒ ✂ ✛ ✞ ☎ ✄ ✄ ✂ ✜ ✞ ✛ ✒ ✔ ✙ ✒ What Does Quality Mean? • Operational meanings: CISC 323: Intro to Software – Software does what is wanted and expected Engineering – On budget and on schedule ✤✦✥★✧✪✩✬✫✮✭✰✯✲✱✴✳✮✵✶✭✸✷✺✹✻✩✽✼ – Users are happy – Level of bugginess is tolerable – Changes are not too expensive – Software is cost-effective in use and supports ☎✝✆✞✝✟ ✎✓✒ ☎✝✆✞✝✟ organizational mandate ✎✓✒ Definitions of Quality Quality is Relative • OED: the standard of something when compared to other • Rolls Royce: quality when cost is no object things like it (a wine of excellent quality); of high quality, • Ford Taurus: quality tradeoffs when cost general excellence is a factor • Crosby: zero defects • Mini: minimum acceptable quality when • ISO: The totality of features and characteristics of a product cost is the dominant factor. or service that bear on its ability to satisfy specified or implied needs. • Costs include initial cost, cost of operation, and • Juran: Fitness for Purpose cost of repairs. • DoD: The degree to which the attributes of the software enable it to perform its intended end use. ☎✝✆✞✝✟ ✎✓✒ ☎✝✆✞✝✟ ✎✓✒ Quality -- General Characteristics of Software • is multidimensional (all aspects of a car) • not physical • is subject to constraints (e.g. cars must fit on • needs are usually uncertain roads) • needs change • is about acceptable compromises (e.g. poorer • platforms change (CPUs, OS, network) ride for lower cost) • high expectations, especially of adaptability • criteria are not independent (e.g. fuel use vs. vehicle weight) • is not absolute (all levels of cars have quality) ☎✝✆✞✝✟ ✎✓✒ ☎✝✆✞✝✟ ✎✓✒ 1