A statechart joins behavior to architecture, very similar to an old-fashioned state transition diagram. Statecharts have additional structure and constraints so that they unambiguously define the movement from one state to the next. A statechart is very similar to an old-fashioned state transition diagram. They have an architectural aspect because your code will likely be built along the lines indicated by the objects you define, even if you don't use code generation or object-oriented programming languages. And they have a collaborative aspect because properly designed objects are intended to pass messages to one another.
Sequence diagrams illustrate the way different components of a system collaborate.
They show the flow of data and control between different aspects of the system as the application executes. Once you've gained experience, you can expect your productivity over manual coding to improve by about fifty percent. For those who want to incorporate existing Java code, or rewrite some of the generated code manually, Rhapsody in J can encapsulate changes to the code, incorporate them back into the model, thus keeping the model and code synchronized. If you need to pursue system views beyond these four, you must look elsewhere for tools, possibly committing to the entire Rational Unified Process. Using all nine UML views is probably most appropriate for complex and highly interactive software systems.