Audit trial means the situation where the input can relate with its output on one-to-one basis,

The work of an auditor would be easy if audit trail is maintained.

In first and early second-generation computer systems, such a complete and trail was generally available, no doubt, to management’s own healthy skepticism of what the new machine could be relied upon to achieve – an attitude obviously shared by the auditor.

It is once iterated that there is an abundance of documentation upon which the auditor can use his traditional symbols of scrutiny, in the form of colored ticks and rubber stamps. Specifically:

(i) The output itself is as complete and as detailed as in any manual system.

(ii) The trail, from beginning to end, is complete, so that all documents may be identified by located for purposes of vouching, totalling and cross-referencing.

Any form of audit checking is possible, including depth testing in either direction.