Automation testing tools are important for automating repetitive tasks and regression testing to save time and costs. However, 100% automation is not possible and manual testing is still needed as humans can detect more problems and cope with complexity. When planning for automation, early consideration in test plans is important so development teams can ensure testable code and tools are selected before projects start. Both automated and manual testing are necessary, with automation best for narrow test scopes and manual testing dealing with complex and adaptive scenarios.