Analysis
The process of understanding a problem
Object-Oriented Analysis
It is a requirements analysis technique
Models real-world objects based on their descriptions
and produces an object analysis model (
Why are objects a better starting point than functions in OOA?
During maintenance, functions change more frequently than objects
What do structured analysis and design techniques focus on?
They are Functionally oriented, which is they focus on the computations that need to be made
What does object oriented analysis and design techniques focus on?
They are primarily concerned with data objects
OOA Class Object Mapping
Takes a textual representation like a requirements document and cuts it up into Identifying words and maps them to descriptions of classes and their relationships
Nouns => Classes
Actions => Operations
Adjectives => Attributes
Stative Verbs => Relationships
Steps in OOA?
- Candidate object classes are indicated by the occurrence of nouns in natural language description of the system
- Nouns are organize into related groups (Classes)
- Adjectives are modeled as Attributes
- Action Verbs are modeled as operations and assigned to appropriate provider class
- Other stative verbs are indicative of relationships
OOA Technique
- Obtain/prepare textual description of the problem
- –> Underline all nouns
- Organize nouns into groups to become candidate classes
- –> Underline all adjectives
- Assign adjectives as attributes of candidate classes
- –> Underline verbs, differentiating action from stative
- Assign action verbs as operations of classes
- –> Assign Stative verbs as attributes of classes or relationships.
Stemming
Removing the prefixes and suffixes, and preserves the root word as a candidate class name.
Class Definition
A description of a group of related objects (aka instances)
Groups
a collection of objects that have some relation.
groups form candidate classes
Operation
Computational service provided by an object.
Suggested by looking for action verbs.
Linking Verbs
Verbs typically associated with the word ‘is’
Stative Verbs
Indicative of a relationship among objects
Relationships
Indicated by lines connecting classes adorned in one of three ways
Ways Relationships are Displayed
- Generalization
Open Triangle - Aggregation
Open Diamond - Association
No Adornment
Generalizations
Instance of one (child) are a kind of instance of the other class.
(inheritance)
Key Words: is a, kind of, type of
Aggregations
Collections of some sort
Key Words: consists of, part of, contains, has, incorporates, belongs to
Association
Stative verbs denote a state of being, and often indicate associations
Stative Verbs
Denote a state of being.
I go to school at KSU.
Counter counts the leaves.
The count is zero.
