Reviews and inspections are static testing techniques. They are can even be ran before the code is working.

The emphasis is on a structured examination of the system and technical documentation.

An important point in inspecting is that any document can be reviewed.

The big selling point for inspections and reviews is that they can find defects much earlier in the development process. This is then extrapolated to conclude that the defects are cheaper to fix.

Defects that are discoverable using these techniques include; uncalled functions and procedures, unreachable code, undeclared variables, array bound violations and parameter type mismatches.

The objective of any review is to obtain reliable information, usually as to status and/or work quality. [Hetzel 88 - p48]

There are 4 recognised types of review or inspection:- Walkthroughs, informal reviews, technical reviews and inspections.

Walkthroughs
Usually led by the author of the document, a walkthrough might exercise typical scenarios or dry run through the code. Documentation and minutes are not kept of the meeting. Indeed the document is marked up and then reworked.

Informal Reviews
A fine distinction is between a walkthrough and informal review. In informal reviews there is preparation phase during which the reviewers identify possible problems.

Technical Reviews
The technical review is more rigorous. A well defined process and generates records of errors and action to be taken. The centrepiece is the review meeting. Chaired and with specific roles such as a technical expert.

Inspections
An extremely demanding process, documents are examined in great detail. Documentation and metrics are generated, both to record process and to improve the process. The Inspection regime was started at IBM.