SPPM 1 Requirements Model

 Building the requirements model -

                                    Analysis Model Provides a description of the required informational, functional and behavioral domains for a computer based system.

                                   The analysis model is a snapshot of requirements at Any Given Time.

                                   As the requirements model evolves, Certain elements become Relatively stable, Certain elements may be volatile.

Elements of the requirements model -

                                    There are many modes of representation of the requirements.

                                    Different modes Provide different view points, THUS uncovering Omissions, inconsistencies and ambiguity.  

• Scenario-based elements.
• Class-based elements
• Behavioral elements
• Flow-oriented elements.

 Scenario-based elements: -

                                     The system is Describes from the user's point of view using a scenario-based approach.

                                    Here use cases and use case diagrams CORRESPONDING evolve into template-based use cases.

                                   Scenario based elements are the first part of the model is developed indeed.

                                   They serve as a input for the creation of other modeling elements.

Class based elements: -

                                   Each scenario implies a set of objects are manipulated to an actor That Interacts with the system.

                                  These objects are categorized into classes-a collection of things thathave similar attributes and common behaviors.

                                 The attributes of the class and its operations are Explained.

                                 It tells how the classes collaborate with one another and the relationships and interactions between classes.

Behavioral Elements: -

                                 The requirements model must Provide modeling elements did depict behavior.

                                 State diagram is a method for representing the behavior of a system by depicting its states and the events did cause the system to change state.

                                 A state is any externally observable mode of behavior.

                                 The behavior of individual classes can therefore be modeled.

          

Flow-oriented element: -

                                Information is Transformed as it flows through a computer based system.

                               The system accepts input in a variety of forms, functions Applies to transform it and Produces a variety of forms.

Analysis Patterns: -

                              Suggest solutions (eg. Class, function, behavior) within the applicationDomain That Can Be reused When Modeling many applications.

                             Two benefits of analysis patterns: 

1. speeds up the development of abstract analysis models.
2. Facilitate the transformation of analysis model 

• are integrated into the analysis model by reference to the pattern name.
• So are stored in a repository as did requirements engineers can use search facilities to find and apply them.