Analysis Principle- Modelling
Software Development Team first check the type of entity for which model has to make is either physical entity of software entity.
Physical Entity: Physical thing like a building, a plane, a machine, engineers at make a functional model that is identical in form and shape but smaller in scale.
Software Entityecure Entity: In this model must be capable of representing the information that software transforms, the functions (and sub functions) that enable the transformation to occur, and the behavior of the system as the transformation taking place.
The second and third operational analysis principles requires that we build models of functions and behavior.
Software transforms information, and it needs to perform three generic functions.
The functional model begins with a single context level model(i.e name of the software to be built).s over a series of iterations, more and more functional details is provided, until a thorough delineation of all system functioning is represented.
Most software responds to events from outside world. This stimulus response characteristics from the basis of the behavioral model.
A computer program always exists in some state - An Externally observable mode of behavior(example computing, printing, polling, waiting) that is changed only when some event occurs.
Software will remain in the wait state until all these happens:
• An internal clock indicates that sometime interval has passed.
• An external event (example Mouse movement) cause an interrupt.
• An external system signals the software to act the same manner.
A behavioral model creates are representation of the states of the software and the events that causes a software to change state.