Is testing a distinct phase of the project, or does it comes into play during other phases? Please explain. How can tools help the quality and effectiveness of testing? Based on Walsh’s (2007) article, explain

Is testing a distinct phase of the project, or does it comes into play during other phases? Please explain. How can tools help the quality and effectiveness of testing? Based on Walsh’s (2007) article, explain why end user satisfaction should be used in addition to ROI when measuring new systems.