Definition
A review of requirements, designs or code characterised by the author of the object under review guiding the progression of the review.
[Source: BCS]
Comment
Walkthroughs ensure that designs and code are reviewed and scrutinised as soon as practically possible after they have been developed and before they are being formally tested. They are a very effective way of finding bugs
On many programmes and large projects, testing will take up a significant portion of the budget. But it will receive less management attention than an activity of this size warrants.