The objective of CASE tools is to add the system analysts and designers to construct high quality systems on time and within budget which can be maintained economically and changed rapidly. CASE tools empower the system analysis and designers freeing them to concentrate upon the truly creative aspects of analysis and design. There are some things that these tools can do and some things that they cannot do. For example, when we use an object program to show a scenario with a message being passed from one object to another, a tool can ensure that the message is in fact part of the object‘s protocol. This is, a tool can perform consistency checking. For example, if we say that there are no more than three instances of this class, a tool can enforce this statement. Similarly a tool can tell us if certain classes or methods are never used.
Some sophisticated tools can also tell us how long it takes to complete a certain operation, or whether or not a certain state in a state transition diagrams is reachable. But a tool cannot tell us that we need to invent a new class so as to simplify our class structure, which requires human intellect.
Visual development tools allow system developers to build user interfaces, reports and other features in a fraction of time. Development tools like Visual Basic, Power Builder, and Delphi etc. allow development of new systems piecing together predefined visual objects rather than typing crude programming commands. As a result more powerful systems could be developed in a fraction of the time previously required.