A competitive product review should always be completed at the beginning of any design project. It informs the designer of the marketplace in which the product will compete, as well as informing the team to the successes and failures of the competitors.
If the project focuses on a redesign of an existing product, then an heuristic evaluation of the existing product should be conducted as well. An heuristic evaluation is a method in which a reviewer, examines the interface and evaluates it based on a set of recognized usability principles, or “heuristics.” Heuristic reviews are typically performed on existing products in order to determine areas that require attention. During the design process, newly designed or revised pages and functional areas should be heuristically reviewed prior to implementation or usability testing.