Precision analysis is very important for key software to improve security

and needs to be automated because of large computing. Based on J M Voas'notional model of Fault/Failure and the PIE analysis

this paper develops a practical technology and presents an automated tool to analyze software code in detail

it describes the whole work flow of precision analytical process

especially the automated analysisrecord phase and the notional arithmetic of three key anabses:execution

infection

propagation

and gives frame diagram of the tool. What is more

it presents the idea of adjustable granularity

which can change the precision class and analysis range

has in a way overcome the limits of Fault/Failure model and expands the possible applications. At the end

it also points out some applications such as to place assertion

estimate teliability

configure resource

design test case

and mention the elicitation to OO software testing.