VIVA QUESTIONS
1.What is UML?
UML stands for Unified Modeling Language which is used in object oriented software
engineering. Although typically used in software engineering it is a rich language that can be
used to model an application structures, behavior and even business processes.
2. List the UML diagrams.
 Class Diagram
 Component Diagram
 Deployment Diagram
 Object Diagram
 Package Diagram
 Use Case Diagram
 Activity Diagram
 State Machine Diagram
 Sequence Diagram
3.What is object oriented analysis and design?
During object-oriented analysis there is an emphasis on finding and describing the objects or
concepts in the problem domain.
During object-oriented design (or simply, object design) there is an emphasis on defining
software objects and how they collaborate to fulfill the requirements.
4. What is an object diagram?
Object Diagrams, sometimes referred as Instance diagrams are very similar to class diagrams.
As class diagrams they also show the relationship between objects but they use real world
examples. They are used to show how a system will look like at a given time. Because there is
data available in the objects they are often used to explain complex relationships between
objects.
5.What is use case diagram?
Use case diagrams model the functionality of a system using actors and use cases. Use cases are
services or functions provided by the system to its users.
6.What is an use case?
It is an interaction between user and system.Use cases are scenarios for understanding system
requirements.Each use case must have the name inside or outside the symbol. It is represented
by ellipse(oval) symbol.
Deposit
7. What is class diagram?
Class diagrams are the backbone of almost every object-oriented method including UML. They
describe the static structure of a system.
8. What is activity diagram?
Activity diagrams represent workflows in an graphical way. They can be used to describe
business workflow or the operational workflow of any component in a system. Sometimes
activity diagrams are used as an alternative to sate machine diagrams.
9. What is package diagram?
Package diagrams organize the elements of a system into related groups to minimize
dependencies among them.
10. Define coupling.
Coupling is a measure of the strength of association established by a connection from one
object or software component to another. Coupling is a binary relationship. Coupling deals with
interactions between objects or software components.
11.What is interaction diagram? Mention the types of interaction diagram.
Interaction diagrams are diagrams that describe how groups of objects collaborate to get the
job done interaction diagrams capture the behavior of the single use case, showing the pattern
of interaction among objects.
There are two kinds of interaction models
• Sequence Diagram
• Collaboration Diagram.
12. What is sequence Diagram?
Sequence diagram is an easy and intuitive way of describing the behaviors of a system by
viewing the interaction between the system and its environment.
13. What is collaboration diagram?
Collaboration diagram represents a collaboration, which is a set of objects related in a
particular context, and interaction, which is a set of messages exchanged among the objects
with in collaboration to achieve a desired outcome.
14. Define start chart diagram.
Start chart diagram shows a sequence of states that an object goes through during its life in
response to events. A state is represented as a round box, which may contain one or more
compartments. The compartments are all optional.
15. What is meant by implementation diagram?
Implementation Diagrams show the implementation phase of systems development such as the
source code structure and the run- time implementation structure.
There are two types of implementation diagrams:
1. Component Diagrams
2. Development Diagrams.
16. Define component diagram.
A Component diagrams shows the organization and dependencies among a set of components.
A component diagrams are used to model the static implementation view of a system. This
involves modeling the physical things that reside on a mode, such as executable, libraries,
tables, files and documents.
17. Define deployment diagram.
Deployment diagram shows the configuration of run-time processing elements and the
software components, processes, and objects that live in them.
Deployment diagrams are used to model the static deployment view of a system. A deployment
diagram is a graph of modes connected by communication association.
18. What is an association?
An association is a relationship between classes (more precisely, instances of those classes) that
indicates some meaningful and interesting connection.
19. What is an attribute?
An attribute is a logical data value of an object. It is useful to identify those attributes of
conceptual classes that are needed to satisfy the information requirements of the current
scenarios under development.
Example: name, age and weight are attributes of Person class.
20. What is a derived attribute?
One attribute is derived from the information of another attribute. In order to communicate
UML convention symbol ( / ) is used before the attribute name.
21. What is generalization?
Generalization is the activity of identifying commonality among concepts and defining
superclass (general concept) and subclass (specialized concept) relationships.
22. What is aggregation?
Aggregation is a vague kind of association in the UML that loosely suggests whole-part
relationships (as do many ordinary associations). It has no meaningful distinct semantics in the
UML versus a plain association, but the term is defined in the UML.
23. What is composition?
Composition, also known as composite aggregation, is a strong kind of whole-part aggregation
and is useful to show in some models. A composition relationship implies that 1) an instance of
the part belongs to only one composite instance at a time, 2) the part must always belong to a
composite and 3) the composite is responsible for the creation and deletion of its parts either
by itself creating/deleting the parts, or by collaborating with other objects.
24. Define classifier.
A UML classifier is a model element that describes behavioral and structure features .Classifiers
can also be specialized. They are a generalization of many of the elements of the UML, including
classes, interfaces, use cases, and actors. In class diagrams, the two most common classifiers
are regular classes and interfaces.
25. What is qualified association?
A qualified association has a qualifier that is used to select an object (or objects) from a larger
set of related objects, based upon the qualifier key.
26. What is a communication diagram?
Communication diagrams illustrate object interactions in a graph or network format, in which
objects can be placed anywhere on the diagram
27. Define event with an example.
An event is a significant or noteworthy occurrence. For example:
A telephone receiver is taken off the hook.
28. Define state with an example.
A state is the condition of an object at a moment in time the time between events. For
example:
A telephone is in the state of being \"idle\" after the receiver is placed on the hook and until it
is taken off the hook.
29. Define transition with an example.
A transition is a relationship between two states that indicates that when an event occurs, the
object moves from the prior state to the subsequent state. For example:
When the event \"off hook\" occurs, transition occurs on the telephone from the \"idle\" to
\"active\" state.
30. What is multiplicity?
Multiplicity defines how many instances of class A can be associated with one instance of a
class B.
31. What is 100% rule?
100% of the conceptual Superclass’s definition should be applicable to the subclass. The
subclass must conform to 100% of the Superclass’s:
 attributes
 associations
32. What is an abstract use case?
It is not complete and has no actors to initiate it , but is used by another use case. It has uses or
extends relationship.
33. Define dynamic model.
It can be viewed as a collection of procedures or behaviors that taken together reflect the
behavior of a system over time. Dynamic modeling is the most useful during the design and
implementation phases of the system development.
34. What is qualified Association?
A qualifier may be used in an association; it distinguishes the set of objects at the far end of the
association based on the qualifier value. An association with a qualifier is a qualified
association.
35. Explain package dependency.
If a model element is in some way dependent on another, the dependency may be shown with
a dependency relationship which is depicted with arrowed line.
A package dependency indicates elements of the dependent package know about or are
coupled to elements in the target package
36. What is UML classifier?
A UML classifier is “a model element that describes behavioral and structure features”
Classifiers can also be specialized. They are a generalization of many of the elements of the
UML, including classes, interfaces, use cases, and actors. In class diagrams, the two most
common classifiers are regular classes and interfaces.
37. What are the ways to show UML attributes?
Attributes of a classifier (also called structural properties in the UML) are shown in several
ways:



attribute text notation, such as currentSale : Sale.
association line notation
both together
38. What is meant by composition and aggregation?
Composition is a special type of aggregation that denotes a strong ownership between Class A,
the whole, and Class B, its part. Illustrated with a filled diamond. A hollow diamond is used to
represent a simple aggregation relationship, in which the "whole" class plays a more important
role than the "part" class, but the two classes are not dependent on each other. The diamond
end in both a composition and aggregation relationship points toward the "whole" class or the
aggregate.
39. Say about interface.
The UML provides several ways to show interface implementation, providing an interface to
clients, and interface dependency (a required interface). In the UML, interface implementation
is formally called interface realization .
40.Define association class.
An association class allows you treat an association itself as a class, and model it with
attributes, operations, and other features. For example, if a Company employs many Persons,
modeled with an Employs association, you can model the association itself as the Employment
class, with attributes such as startDate.
41.What is Responsibility Driven Design(RDD) approach?
In RDD,we think about the design of Software Objects as having responsibilities – an abstraction
of what they do. The UML defines a responsibility as “a Contract or Obligation of a Classifier
42. What is behavior of an object?
Behavior is how an object acts and reacts in terms of its state changes and message passing.
43. What is visibility?
Visibility is the ability of one object to see or have reference to another. In general, visibility is
the ability of an object to "see" or have a reference to another object. More generally, it is
related to the issue of scope: Is one resource (such as an instance) within the scope of another?
44. What is transition action?
A transition can cause an action to fire. In a software implementation, this may represent the
invocation of a method of the class of the state chart diagram.
45. Define lifelines.
Lifelines are vertical dashed lines that indicate the object's presence over time.
46. Define actors.
Actors are the users of a system. When one system is the actor of another system, the actor
system is labeled with the actor stereotype.
47. What are post conditions?
It describes changes in the state of objects in the domain model that are true when the
operation has finished. They are not actions to be performed during the operation . Post
conditions fall into these categories :

Instance creation and deletion

Attribute modification

Associations (UML links) formed and broken.
48. What are the two types of node in deployment diagrams?
 device node (or device)
 execution environment node (EEN)
49. Say about initial and final state in activity diagram.
Initial State: A filled circle followed by an arrow represents the initial action state.
Final State: An arrow pointing to a filled circle nested inside another circle represents the final
action state.
50. Define a component.
A component represents a modular part of a system that encapsulates its contents and whose
manifestation is replaceable within its environment. A component defines its behavior in terms
of provided and required interfaces. As such, a component serves as a type, whose
conformance is defined by these provided and required interfaces