(B) What is UML?
The Unified Modeling Language (UML) is a graphical language for visualizing,specifying,
constructing, and documenting the artifacts of a software-intensive system.UML provides
blue prints for business process,System function,programming language
statements,database schemas and reusable components.
(I) How many types of diagrams are there in UML ?
Twist :- Explain in short all types of diagrams in UML ?
There are nine types of diagrams in UML :-
Use case diagram:
They describe "WHAT" of a system rather than "HOW" the system does it. They are
used to identify the primary elements and processes that form the system. The primary
elements are termed as "actors" and the processes are called "use cases." Use Case diagrams
shows "actors" and there "roles".
Class diagram:
From the use case diagram we can now go to detail design of system, for which the
primary step is class diagram.The best way to identify classes is to consider all "NOUNS"
in use cases as classes , "VERBS" as methods of classes, relation between actors can
then be used to define relation between classes.The relationship or association between
the classes can be either an "is-a" or "has-a" relationship which can easily be identified
from use cases.
Object diagram:
An object is an instance of a class.Object diagram captures the state of classes in the
system and their relationships or associations at a specific point of time.
State diagram:
A state diagram, as the name suggests, represents the different states that objects in the
system undergo during their life cycle.Object change in response to certain simulation so
this simulation effect is captured in state diagram.So basically it has a initial state and
final state and events that happen in between them.Whenever you think that some
simulations are complicated you can go for this diagram.
Sequence diagram:
Sequence diagrams can be used to explore the logic of a complex operation, function, or
procedure.They are called sequence diagrams because sequential nature is shown via
ordering of messages.First message starts at the top and the last message ends at bottom. The
important aspect of a sequence diagram is that it is time-ordered. This means that the
exact sequence of the interactions between the objects is represented step by step. Different
objects in the sequence diagram interact with each other by passing "messages".
Collaboration diagram:
A collaboration diagram groups together the interactions between different objects to
fulfill a common purpose.
Activity diagram:
Activity diagram is typically used for business process modeling, for modeling the logic
captured by a single use case , or for visualizing the detailed logic of a business
rule. Complicated process flows in the system are captured in the activity diagram. Similar
to a state diagram, an activity diagram also consists of activities, actions, transitions,
initial and final states, and guard conditions.But difference is state diagrams are in context
of simulation while activity gives detail view of a business logic.
Deployment diagram:
Deployment diagrams show the hardware for your system, the software that is installed
on that hardware, and the middleware used to connect the disparate machines to one
another.It shows how the hardware and software work together to run a system. In one
line its shows the deployment view of the system.
Component diagram:
The component diagram represents the high-level parts that make up the system.From
.NET angle point of view they form the "NAMESPACES".This diagram depicts, at a
high level, what components form part of the system and how they are interrelated. Its
shows the logical grouping of classes or group of other components.
(B) What are advantages of using UML? Twist: - What is Modeling and why UML ?
As the name suggest UNIFIED MODELING LANGUAGE.Modelling has been around
for years, not only in software field but also in other trades like civil, mechanical etc.
Example in civil engineering drawing the main architecture built of diagram is a model by
itself.Modelling makes complex and huge system to break up in to simple and discrete
pieces that can be individually understood. Example simple flowchart drawing is modeling.
There are two main advantages of modeling:-
√ Readability: - Representing your whole architecture in flowchart, class diagrams,
ER diagrams etc makes your project more readable. Especially when
programmer’s change jobs handover becomes easier. More the project is not
readable more the dependencies.
√ Reusability: - After the system is more readable and broken down to pieces, it
becomes easier to identify redundant and similar modules. Thus increasing
reusability.
So why UML, well different language’s have different ways of coding and syntaxes. In
order to bring all languages in one roof UML is in to picture. As the term comes in
UNIFIED, it unifies all disparate languages in one roof so that can be understood by
people who are working on some other platforms.
(A)Give a small brief explanation of all Elements in activity diagrams?
Action State :- It is a type of state that has an internal action and one outgoing event that
completes the internal action. State :- It’s a condition when following events occur:-
√ Object satisfies a condition.
√ Or performs a action.
√ Or waits for a event to happen. Initial State:- It represents a state before any event occurs. Final State:- Represents completion of an activity. Transition Fork::- Denotes beginning of parallel path activities. Transition Join: - Denotes merging of parallel path activities. Control Flow: - Represents relationship between two states and actions. In short it indicates
that an object in one state is entering some other state. Object Flow: - Connects an object flow state to control flow or action state. Object in State: - Indicates an object state after manipulation by multiple activities. Decisions: - Defines if there are any condition’s in the path. Swim Lanes: - Assigns responsibility to action states. Signal receipt Shape: - Used to replace an event label on a transition. Signal Send Shape: - Used to replace an event label on a transition. Constraint: - Condition’s that must be maintained true in order the system is valid. 2-Element Constraint: - It shows a constraint on two classes or associations. OR constraint: - It shows an OR constraint on two classes or associations.
(A) Explain Different elements of a collaboration diagram ?
Classifier Role :- It classifies a role. Association Role :- It shows relation between two classifier roles. Multi-Object :- It used to show operation related to entire set of objects rather than on a
single object. Constraint :- Condition’s which must be maintained as true in order that system is valid. 2-Element Constraint: - It shows a constraint on two classes or associations.
OR constraint: - It shows an OR constraint on two classes or associations.
(A) Explain Component diagrams ? Package: - It logically groups element of a UML model. Component: - It’s the actual implementation or physical module of a UML system. Node: - A physical system which represents a processing resource.Example PC or a host
machine. InterFace :- It specifies the externally operations of a class, component, package, or other
element without specifying internal structure. Dependency :- Shows relationship between two elements. 2-Element Constraint: - It shows a constraint on two classes or associations.
OR constraint: - It shows an OR constraint on two classes or associations.
(A) Explain all parts of a deployment diagram? Package: - It logically groups element of a UML model. Node: - A physical system which represents a processing resource. Example PC or a host
machine. Component: - It’s the actual implementation or physical module of a UML system. Node instance: - It’s a runtime physical instance of a processing resource. Component Instance: - It represents an implementation unit that has identity at run time
and can contain objects. A component could be contained within a node instance. InterFace :- It specifies the externally operations of a class, component, package, or other
element without specifying internal structure. Object: - Instance of a class. Composition shape: - It is a form of aggregation that indicates that a part may belong to
only one element or life time of the element. Communication: - How an actor Dependency: - Shows relationship between two elements. 2-Element Constraint: - It shows a constraint on two classes or associations. OR constraint: - It shows an OR constraint on two classes or associations.
(A) Describe various components in sequence diagrams? Object lifeline: - It represents the lifetime of object creation and its destruction. If the
object is created or destroyed during the time period the diagram represents, then the
lifeline stops or starts at the appropriate point. An object's destruction is marked with a
large X. Activation: - It’s time period during which actor is performing a action. Lifeline :- This say’s that there exist some condition on the object lifetime. Message: - It shows communication between objects that conveys information and results
in an action. Message (call):- Its same like message but also conveys some information and results in
action.
All messages have same definition as the Message (Call) given above. 2-Element Constraint: - It shows a constraint on two classes or associations. OR constraint: - It shows an OR constraint on two classes or associations.
(A) What are the element in State Chart diagrams ? State: - It’s a condition when following events occur:-
√ Object satisfies a condition.
√ Or performs a action.
√ Or waits for a event to happen. Composite State :- It has one or more substates. Initial State: - It represents a state before any event occurs. Final State: - Represents completion of an activity. Transition :- Shows the change of one state to other. Transition Fork: - Denotes beginning of parallel path activities. Transition Join: - Denotes merging of parallel path activities. Decision: - Indicates condition to move to different states. Shallow History: - Represents the state last visited. When a transition to the indicator
fires, an object resumes the state it last had at the same level as the history indicator. Deep history: A deep history allows you to return from whatever sub-state,
whereas a shallow one only remembers the initial state of a composite state. 2-Element Constraint: - It shows a constraint on two classes or associations. OR constraint: - It shows an OR constraint on two classes or associations.
(A)Explain different elements of a Use Case ? Package: - It logically groups element of a UML model. Use Case :- It represents a set of events. Actor : - Role played by an outside object. Interface :- It specifies the externally operations of a class, component, package, or other
element without specifying internal structure. Communication: - How an actor Dependency shows relationship between two elements. Extends: - Indicates that the elements come in parent child relationship where one element
inherits other elements behavior. Uses: - Here one element uses the other elements behavior.The main difference between
Extends and Uses is a “Is a” and “Has a” relationship.” Is a “relationship defines a child
parent relationship. Example “XYZ” is a child of “PQR”.”Has a” relationship defines an
aggregation relationship that “XYZ” has a “BLUE SHIRT”. System boundary: - Indicates the system boundary of a Use case. 2-Element Constraint: - It shows a constraint on two classes or associations. OR constraint: - It shows an OR constraint on two classes or associations.
