Test estimation is the process of predicting the effort, time, and resources required for testing a software system. Test estimation depends on several factors that influence the scope, complexity, and quality of testing. Some of these factors are:
Characteristics of the product: This factor indicates how difficult or challenging it is to test the software system based on its size, functionality, reliability, usability, performance, security, etc.
Characteristics of the development process: This factor indicates how well or poorly the software system is developed based on the development methodology, standards, tools, techniques, etc.
Characteristics of the test process: This factor indicates how effective or efficient the testing process is based on the test strategy, plan, design, execution, evaluation, etc.
Characteristics of the test team: This factor indicates how skilled or experienced the test team is based on their knowledge, competence, motivation, communication, collaboration, etc.
The outcome of testing of previous test cycle is not a factor on which test estimation is dependent upon because it does not affect the effort, time, or resources required for testing the current test cycle. Rather, it is an outcome or consequence of test estimation that can provide feedback and lessons learned for improving future test estimations. You can find more information about test estimation in Software Testing Foundations: A Study Guide for the Certified Tester Exam, Chapter 22.
