Factors that are important to take into account when performing test estimation include:i.

Comprehensive and Detailed Explanation From Exact Extract of ISTQB Certified Tester Advanced Level – Test Manager v3.0 syllabus:

Product characteristic → quality of the test basis (C = i):The syllabus lists the quality and stability of the requirements/specifications (test basis) as a product-related estimation driver.

Test results characteristic → amount of rework (B = iii):Expected rework/defect-fix cycles and their impact on retesting and confirmation testing are identified through past results/defect patterns and directly affect estimates.

Test context characteristic → distribution across locations (A = iv):Organizational and logistical context (multiple sites, time zones, communication overhead) influences test effort.

Development process characteristic → availability of test automation (D = ii):Process/tooling capability (e.g., presence of automation frameworks) is treated as a development/process factor affecting test efficiency and thus estimation.The syllabus groups estimation drivers into characteristics such as product, development process, test results/history, and test/organizational context, and recommends mapping specific factors to these groups to structure estimation.

===========