This document discusses building a requirements model and its elements. It explains that a requirements model provides a description of required information, functions, and behaviors for a computer system, and will change as stakeholders' understanding evolves. The model contains scenario-based elements like use cases and user stories, class-based elements like class diagrams that define objects and relationships, behavioral elements like state diagrams that represent system states and events, and flow-oriented elements like data flow diagrams that show how data is transformed through the system.

1. NADAR SARASWATHI COLLEGE OF ARTS & SCIENCE,
THENI.
SOFTWARE ENGINEERING.
BUILDING THE REQUIREMENTS MODEL
&
ELEMENTS OF THE REQUIREMENTS MODEL.
By,
R.Preethi.

2. BUILDING THE REQUIREMENTS MODEL:
The intend of the analysis model is to
provide a description of the required
information, function and behavioral
domains for a computer based system.
The model changes dynamically as you
learn more about the system to be built,
and other stakeholders understand more
about what they really require.

3. For that reason, the analysis model is a
snapshot of requirements at any given time .
you should expect it to change.
As the requirements model evolves, certain
elements as will become relatively stable,
providing a solid foundation for the design
tasks that follow.
Other elements of the model may be more
volatile, indicating that stakeholders do not yet
fully understand requirements for the system.

4. ELEMENTS OF THE REQUIREMENTS MODEL:
Scenario based element
Class based element
Behavioral based element
Flow oriented element

5. Scenario based element:
This type of element represents the system
user point of view.
Scenario based elements are use case
diagram, user stories.

6. Class based elements:
The object of this type of element manipulated
by the system.
It defines the object, attributes and relationship.
The collaboration is occurring between the
classes.
Class based elements are the class diagram,
collaboration diagram.

7. Behavioral elements:
Behavioral elements represent state of the
system and how it is changed by the external
events.
The behavioral elements are sequenced
diagram, state diagram.

9. Flow oriented elements:
An information flows through a computer-
based system it gets transformed.
It shows how the data objects are transformed
while they flow between the various system
functions.
The flow elements are data flow diagram,
control flow diagram.
