Reviews are conducted throughout the SDLC with development reviews focusing on code and its related products.
Design and code reviews held during the course of the various phases are usually in the form of walk-throughs and inspections. These are held to get an early start on the elimination of defects in the products being examined. They are generally informal, which makes them more productive and less threatening to the egos and feelings of the producers of the products being reviewed.
Test reviews are much the same as code reviews, covering the test program products rather than the software products. They include the same types of formal and informal reviews and are held throughout the SDLC. Their function is to examine the test program as it is being developed and to make sure that the tests will exercise the software in such a manner as to find defects and to demonstrate that the software complies with the requirements.