Chapter 4 is the cheapest chapter to prepare and the fastest to bank. It supplies 4 of the 45 questions for 4 of the 78 points, all at K2, with 60 training minutes allocated against the syllabus total of 1,215. Nothing here is applied or analytical — the questions turn on knowing the vocabulary of ISO/IEC 25010 (2023) and knowing which quality characteristics belong to the Test Analyst in the first place.
The chapter walks four characteristic groups. Functional suitability splits into functional completeness, functional correctness and functional appropriateness, and the exam expects you to tell them apart and to know that each is tested differently. Usability is treated as interaction capability under ISO/IEC 25010 plus beneficialness from ISO/IEC 25019, evaluated through usability reviews, usability test sessions built on personas and operational profiles, and questionnaires such as SUMI and WAMMI; accessibility brings in WCAG (2023) levels A, AA and AAA alongside the UK Equality Act 2010 and the US ADA. Flexibility, which the older syllabi called portability, and compatibility close the chapter.
The reliable trap in this chapter is role boundaries. Within flexibility the Test Analyst owns adaptability and installability, while scalability belongs to the performance testing syllabus and replaceability to the Technical Test Analyst. Within compatibility the Test Analyst owns interoperability — data exchange, microservices, IoT, protocol standards — while coexistence belongs to the Technical Test Analyst. Learn those four splits and the chapter mostly answers itself. Our practice pool for it holds 12 questions.
This chapter is covered most heavily (4 questions) in CTAL-TA — Mock Exam 1 (Test Design Techniques Deep Dive), CTAL-TA — Mock Exam 2 (Domain Partitioning, State Models & Risk-Based Test Design), CTAL-TA — Mock Exam 3 (Test Oracles, Combinatorial Design & Defect Metrics)