1. Analysis Classes
Unit 5

2. Key Concepts Analysis class diagram overview
Analysis class stereotypes
Sequence diagrams
Communication diagrams
Adding behaviors to an analysis class
Activity diagrams
State diagrams
Business rules

4. What Is an Analysis Class?
A class that represents initial data and behavior requirements, and whose software and hardware-oriented details have not been specified
Analysis class diagram – a UML diagram showing analysis classes and their relationships

5. Stereotypes of Analysis Classes
Mostly performs behaviors associated with inner workings of use cases
Mostly corresponds to conceptual data model classes
Encapsulates connections between actors and use cases

7. What Is a Sequence Diagram?
UML diagram that shows the interaction between objects to perform critical pieces of use case behavior in a time-ordered manner
Interactions are in the form of messages
Behavioral responsibilities are assigned to message recipients
Boundary Objects send messages to
Actors
Other boundary classes

8. Messages are passed between objects, and may contain parameters

9. Symbols in a Sequence Diagram
Box or class stereotype symbol represents objects.
Dotted vertical line represents object’s lifetime.
Thin bars represent focus of control, periods of time when object is behaving (fulfilling responsibilities).
Labeled horizontal lines represent messages passing between objects.

11. Typically, actors interact with boundary classes, which in turn interact with control classes, which in turn interact with entity classes.

12. What Is Robustness Analysis?
Involves analyzing the narrative text of each of the use cases and identifying a first-guess set of the objects into entity, boundary, and control classes
Requires completeness checks and adherence to diagramming rules

14. Visio Sequence Diagram

15. What Is a Communication Diagram?
A UML diagram that shows the interactions between objects to perform critical pieces of the use case behavior
Unlike sequence diagrams, communication diagrams have no spatial representation of time; sequences of messages are shown by numbering.

17. Drawing Analysis Class Diagrams
Analysis classes are completed by including operations, which fulfill the responsibilities taken by the analysis class.
In addition, attributes and relationships from the conceptual data model are retained and refined.

18. Operations (behaviors) are depicted in the lower third of a class box.
Operations fulfill the class’s responsibilities.

19. What Is an Activity Diagram?
A diagram that emphasizes the flow of control from activity to activity in an object
Similar to the traditional program flowchart
Used to provide detail for complex algorithms

20. Elements of Activity Diagrams
Activity – a behavior that an object carries out while in a particular state
Transition – a movement from one activity or state to another
Decision point – a diamond symbol containing a condition whose results provide transitions to different paths of activities
Swimlanes – lanes that partition the diagram to show who does what activities
Synchronization bar – horizontal or vertical bars denoting parallel or concurrent paths of activities
group group2

21. Activity diagram with the decision points and three swimlanes

22. Activity diagram with synchronization bars
Top synchronization bar is a fork.
Bottom synchronization bar is a join.

23. What is a State Diagram?
A diagram that captures the behavior of an object by specifying the sequence of states it goes through during its lifetime in response to events, together with the responses to those events
Also called statechart diagram
-State – a condition or situation during the life of an object at which time it satisfies some condition, performs some activity, or waits for some event.
-All activities are states

25. When to Use State Diagrams
For describing object behavior across many use cases
Not useful for describing behavior of many objects collaborating together
Not for everybody…some analysts like them and others do not

26. What Is a Business Rule?
A directive that is intended to influence or guide business behavior in support of business policy formulated in response to an opportunity or threat
In information systems, business rules are implemented as data, constraints, and/or program code.

27. Types of Business Rules
Constraints – restrictions, mainly in the form of permissible values, validation rules, and multiplicities
Calculations – mathematical formulas or algorithms that produce some value
Value inferences – establishing the value of an attribute based on a test condition
Action enablers – deciding on an action based on a test condition

28. Approaches for Value Inferences and Action Enablers
Decision Tables
Matrix representation of the logic of decisions, specifying possible conditions and resulting actions
Decision Trees
Node-and link representation of the paths of choices and decisions
Structured English
Verbal description of decision logic
Pseudocode

29. Components of Decision Tables
Condition stub
The part of the decision table that lists the conditions relevant to the decision
Action stub
The part of the decision table that lists the possible actions or values of the decision
Rule
The part of the decision table that specifies the specific mapping of conditions to actions or values

31. Reducing the Decision Table
A complete decision table may have indifferent conditions for certain rules
Therefore, rules can sometimes be combined to simplify the decision table

33. What is Object Contraint Language (OCL)?
An formal, declarative language add-on to UML for writing expressions that unambiguously specify business rules
OCL expressions consist of:
Context – the element for which the expression is defined
Invariant – A constraint that should be true for an object during its lifetime

34. Elements of OCL Expressions
Context – the element for which the expression is defined
For each context, you can specify
Initial values
Derivation rules
Constraints
Query optimizations
Invariants
Pre- and Post-conditions

35. OCL Expressions