A tool is any device, object or a kind of an operation used to achieve a specific task. The complete and correct description of the system is as important as the system itself. The analyst uses case tool to represent and assemble all the information and the data gathered about the system.
Most of the organizations have to follow some kind of procedures and they are required to make all sorts of decisions from time to time. For the job of the analyst both these procedures and decision-making processes of the business system under investigation are equally important.
Expressing business processes and rules in plain text is very cumbersome and difficult process. It requires a lot of effort. Moreover, it does not guarantee if the reader will understand it well. So representing these things graphically is a good choice. So CASE Tools are useful in representing business rules and procedures of organization in graphical way. It requires less effort and it is easy to understand.
Some CASE tools are designed for creating new applications and not for maintaining or enhancing existing ones hence if an organization is in a maintenance mode, it must have a CASE tool that supports the maintenance aspect of the software developed. Many a times the large projects are too big to be handled by a single analyst thus here the CASE too must be compatible enough to allow for partitioning of the project.
Efficient and better CASE tools collect a wide range of facts, diagrams, and rules, report layouts and screen designs. The CASE tool must format the collected data into a meaningful document ready to use.
Tools for DFD or a data flow diagram is a perfect example of a good CASE tool and it will be dealt in the later sessions.