Accelerated analysis approaches emphasize the construction of   （）    to more rapidly identify business and user requirements for a new system. As an accelerated analysis technology，  （） reads the program code and automatically generates the equivalent system model， and the code can be obtained from  （） . All system analysis approaches require some form of  （）  which includes those techniques to be used to identify or extract system problems and solution  requirements  from user community.  （）  is a classical set of  techniques used  to collect information about system problems， opportunities， solution requirements， and priorities.