Understanding Software Quality: Project Management, Quality Definition, and the Six Quality Characteristics

One month after the idea first arose, the author finally writes to share insights on how developers and testers can improve product quality, covering test case design, self‑testing skills, and actions developers can take.

The discussion begins with the three essential elements of project management—cost, schedule, and quality—forming the classic “iron triangle,” and explains how these factors interrelate and must be balanced in real projects.

Quality is defined according to ISO as the degree to which an entity’s characteristics meet explicit or implicit needs, emphasizing the three basic components of an entity, its characteristics, and the requirements (both explicit and implicit).

The article then introduces the software‑quality “iron triangle,” which consists of technology, process, and organization. Technology includes business knowledge, testing theory, test‑case design, performance, automation, and development knowledge. Process defines who does what, when, and how, covering development cycles, bug lifecycles, test workflows, configuration management, and release procedures. Organization concerns personnel recruitment, training, career paths, and knowledge‑sharing mechanisms, influencing both process and technology.

From a technical perspective, software quality is evaluated using six characteristics: functionality, reliability, usability, efficiency, maintainability, and portability. The article focuses on the functionality characteristic, detailing its five sub‑characteristics—suitability, accuracy, interoperability, confidentiality/security, and compliance—and provides concrete examples such as login‑page testing.

Finally, the author summarizes testing thinking: maintain a holistic view of the system’s role and impact, dive into details using test‑case design to cover the six quality characteristics, follow testing principles (error‑finding over verification, early testing, acknowledging that exhaustive testing is impossible), and apply both forward and reverse thinking to uncover hidden bugs, while continuously improving processes and organizational practices.