Author Topic: How we draw a usecase diagram from a case study?  (Read 2604 times)

1171948312

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Re: How we draw a usecase diagram from a case study?
« Reply #15 on: February 14, 2018, 06:50:21 am »
1.Read the case study thoroughly 2-10 times.
2.Understand the actors and actions who are involved in the case study.
3.Write down the primary actors(End User/who interacts with the system) and secondary actors(On whom system dependent on)and the actions involved in the case. Generalize actors and actions involved in the case.
4. Draw a system boundary- usecase
5.Place the primary actors on the left-hand side of the system boundary.
6.Place the secondary actors on the right side.
7. Place the Actions inside the system boundary. Connect the actors and actions in the system and connect the actions which are dependent on secondary actor.
8.Hence we draw Usecase diagram.

1170944412

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Re: How we draw a usecase diagram from a case study?
« Reply #16 on: March 10, 2018, 12:58:54 pm »
Use case diagrams are used to describe the functionality of a system from a top-down perspective. They represent only the positive flow and all the available functionality of the system are shown. There are essentially four major elements of UCDs
The actors, the system, the use cases and the lines that represent the relationship between these elements.
We use the following rules to draw use case diagram
•   Information that we do not model in the use case diagrams are
             Architecture names (2 tier, 3 tier, client server etc)
             Names of the systems (laptop, desktop)
             Brand names (HP, Lenovo etc.)
             Technology used (java, .net etc.)
             Networks (LAN, WAN)
             Databases (SQL, MySQL, etc.)
•   Differentiate between information and actions
•   Write all sequence of actions
•   Try to identify the actors performing the above mentioned actions
•   Try to differentiate between essential use cases and supporting use cases
•   Try to identify some modules with respect to functionality or usage
•   Try to identify the relationships appropriately between the identified actors and the use cases
« Last Edit: March 10, 2018, 01:01:15 pm by 1170944412 »

1180650901

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Re: How we draw a usecase diagram from a case study?
« Reply #17 on: March 25, 2018, 11:07:35 pm »
First and last
Read the case study 2 -3 times because that will give you a picture .

In a very simple or layman :

1. Mark primary actors column
2. Secondary actors column
3. supporting use case
4. essential  use case

Then try to relate it with the case study

1172831810

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Re: How we draw a usecase diagram from a case study?
« Reply #18 on: April 07, 2018, 04:59:16 pm »
The following checklist shows the steps necessary for the construction of use case diagrams from the external view.

  • Collect information sources—How am I supposed to know that?
    Identify potential actors—Which partners and customers use the goods and services of the business system?
    Identify potential business use cases—Which goods and services can actors draw upon?
    Connect business use cases—Who can make use of what goods and services of the business system?
    Describe actors—Who or what do the actors represent?
    Search for more business use cases—What else needs to be done?
    Edit business use cases—What actually has to be included in a business use case?
    Document business use cases—What happens in a business use case?
    Model relationships between business use cases—What activities are conducted repeatedly?
    Verify the view—Is everything correct?


Satish kumar Gajula

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Re: How we draw a usecase diagram from a case study?
« Reply #19 on: April 24, 2018, 04:46:58 pm »
Steps to follow to draw a Use Case diagram from a case study:
1.   Information which we Do Not model in Use Case diagrams are
a)   Name of the systems (Laptops, Desktops, Workstations),
b)   Architectures (2 Tier, 3 Tier, n Tier, Client Server),
c)   Databases Names (DB2, SQL Server, My SQL),
d)   Networks (LAN, WAN, Internet),
e)   Brand Names (HP, Lenovo, Wipro, Sony)
f)   Technology Names (Java, .Net, Mainframes)
2.   Differentiate information against actions
3.   Write all sequence of actions
4.   Try to find out which actor is performing the above action
5.   Try to identity Essential Use Cases and Supporting Use Cases
6.   Try to identity some modules with respect to functionality or usage
7.   Try to draw the relationships appropriately between the identified actors and use cases.

1180654601

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Re: How we draw a usecase diagram from a case study?
« Reply #20 on: June 06, 2018, 10:26:24 pm »
The purpose of use case diagram is to capture the dynamic aspect of a system.Use case diagrams are used to gather the requirements of a system including internal and external influences. These requirements are mostly design requirements. Hence, when a system is analyzed to gather its functionalities, use cases are prepared and actors are identified.

To conclude an use case is used for;'
-Used to gather the requirements of a system.
-Used to get an outside view of a system.
-Identify the external and internal factors influencing the system.
-Show the interaction among the requirements are actors.

Steps to be followed to draw Use case Diagram;
(1) Information which we do not model in Use case diagram are:
Names of the systems (Laptops, Desktops, Work stations).
Architectures (2 Tier, 3 Tier, Client server).
Databases names (DB2, SQL Server, My SQL).
Networks (LAN, WAN, Internet).
Brand Names (Lenovo, Intel, Sony, HP).
Technology Names (Java, C++, Dot Net).
(2) Differentiate information against actions.
(3) Write all sequence of actions.
(4) Try to find out which actor is performing the above action.
(5) Try to identify essential use cases and supporting use cases.
(6) Try to find out modules with respect to functionality or usage.
(7) Try to draw the relationships appropriately between identified actors and use cases.


1183170103

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Re: How we draw a usecase diagram from a case study?
« Reply #21 on: June 15, 2018, 02:18:54 pm »
This is typically my approach ( keeping in mind the step mentioned in the book - i.e., dont model databases, tech, brand names etc)

compile actors and actions into a list. Then, you draw connectors between actors and actions. What you end up with, is a clear visual representation of the relationship between actors and actions. It's really easy after this.

The difficulty lies in identifying the actions and actors without missing anything.

1180364903

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Re: How we draw a usecase diagram from a case study?
« Reply #22 on: June 22, 2018, 08:20:33 pm »

Below are the steps for drawing use case

 - First identify the Actors
 - Second define use case
 - Third define use case behaviour

1181471104

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Re: How we draw a usecase diagram from a case study?
« Reply #23 on: June 27, 2018, 11:39:03 am »
The following steps are followed
1. Information which we do not model in use case diagrams are
    (i) Name of the systems
    (ii) Architectures
   (iii) Database names
   (iv) Networks
   (v) Brand names
   (vi) Technology names
2. Differentiate information against actions.
3. Write all sequence of actions.
4. Try to find out which actor is performing the above section.
5. Try to identify essential use cases and supporting use cases.
6. Try to identify some modules with respect to functionality.
7. Try to draw the diagram appropriately between use cases and actors

1181278305

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Re: How we draw a usecase diagram from a case study?
« Reply #24 on: July 11, 2018, 09:46:30 pm »





Use case diagram will be drawn in perspective of user behavior with the system .The following steps are followed
1. Information which we do not model in use case diagrams are
    (i) Name of the systems
    (ii) Architectures
   (iii) Database names
   (iv) Networks
   (v) Brand names
   (vi) Technology names
2. Differentiate information against actions.
3. Write all sequence of actions.
4. Try to find out which actor is performing the above section.
5. Try to identify essential use cases and supporting use cases.
6. Try to identify some modules with respect to functionality.
7. Try to draw the diagram appropriately between use cases and actors

1170505308

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Re: How we draw a usecase diagram from a case study?
« Reply #25 on: July 15, 2018, 11:23:18 pm »
Information which we do not model in use case diagrams are:
Name of the systems,architectures,databases,networks,systems, brand names

Identifying Actors *

Actors are external entities that interact with system. Actor can be a person, another system or an organization.

Example : In a banking system, the most obvious actor is the customer. Other actors can be bank employee or cashier depending on the role that is planned to be presented in the use case



Identifying Use Cases *

After identifying actors and the next step would be identification of use cases. A good way to do this is to identify that how actors  interact with the system.

Identify Essential use cases and Supporting use cases

Top level use cases should always provide a complete function required by an actor. We can extend or include use cases depending on the complexity of the system.
Once you identify the actors and the top level use case you have a basic idea of the system.

and then we need to draw the relationship appropriately between the identified actors and use cases.

AND ALSO PERFORMING SOME ROLE PLAYS HELPS US IN IDENTIFYING THE REQUIREMENTS WHICH IN TURN HELPS IN DESIGNING THE USE CASE DIAGRAM

FOR understanding of business processes AND POTENTIAL REQUIREMENTS TO BE IDENTIFIED/ANALYSED WE CAN PRACTICE THE FOLLOWING :
 
Brainstorming, Surveys, Role plays, Communicating with the domain matter and subject matter experts, Tools used.

1181280005

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Re: How we draw a usecase diagram from a case study?
« Reply #26 on: July 31, 2018, 02:08:00 pm »
The major elements of use case diagram is after reading the case study.
Actor
Actors are usually individuals involved with the system defined according to their roles. The actor can be a human or other external system.

Use Case
A use case describes how actors uses a system to accomplish a particular goal. Use cases are typically initiated by a user to fulfill goals describing the activities and variants involved in attaining the goal.

Relationship
The relationships between and among the actors and the use cases.

System Boundary
The system boundary defines the system of interest in relation to the world around it.

Home Tutorials Use Case Diagram
What is a Use Case Diagram in UML?
Use Case Diagram Notations
Actor
Use Case
Relationship
System Boundary
Benefits of Use Case Diagram
How to Draw Use Case Diagram?
Structuring Use Cases
Include
Extend
Abstract & Generalization
Business Use Case
Use Case Diagram Examples
Use Case Diagram Tutorial
A use case describes how a user uses a system to accomplish a particular goal. A use case diagram consists of the system, the related use cases and actors and relates these to each other to visualize: what is being described? (system), who is using the system? (actors) and what do the actors want to achieve? (use cases), thus, use cases help ensure that the correct system is developed by capturing the requirements from the user's point of view.

Use Case Diagram Example
What is a Use Case Diagram in UML?
A use case is a list of actions or event steps typically defining the interactions between a role of an actor and a system to achieve a goal. A use case is a useful technique for identifying, clarifying, and organizing system requirements. A use case is made up of a set of possible sequences of interactions between systems and users that defines the features to be implemented and the resolution of any errors that may be encountered.

While a use case itself might drill into a lot of detail (such as, flow of events and scenarios) about every possibility, a use-case diagram can help provide a higher-level view of the system, providing the simplified and graphical representation of what the system must actually do.

A use case (or set of use cases) has these characteristics:

Organizes functional requirements
Models the goals of system/actor (user) interactions
Describes one main flow of events (main scenarios) and possibly other exceptional flows (alternatives), also called paths or user scenarios
Try it!
Finding an online Use Case Diagram tool? Just click the Draw button below to create your Use Case Diagram online. Visual Paradigm Online is free* and intuitive. You can also go through this Use Case Diagram tutorial to learn about Use Case Diagram before you get started.

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Use Case Diagram Notations
Use cases define interactions between external actors and the system to attain particular goals. A use case diagram contains four main components

Use Case Diagram Notations
Actor
Actors are usually individuals involved with the system defined according to their roles. The actor can be a human or other external system.

Use Case
A use case describes how actors uses a system to accomplish a particular goal. Use cases are typically initiated by a user to fulfill goals describing the activities and variants involved in attaining the goal.

Relationship
The relationships between and among the actors and the use cases.

System Boundary
The system boundary defines the system of interest in relation to the world around it.

Benefits of Use Case Diagram
Use cases is a powerful technique for the elicitation and documentation of black-box functional requirements.
Because, use cases are easy to understand and provide an excellent way for communicating with customers and users as they are written in natural language.
Use cases can help manage the complexity of large projects by partitioning the problem into major user features (i.e., use cases) and by specifying applications from the users' perspective.
A use case scenario, often represented by a sequence diagram, involves the collaboration of multiple objects and classes, use cases help identify the messages (operations and the information or data required - parameters) that glue the objects and classes together.
Use cases provide a good basis to link between the verification of the higher-level models (i.e. interaction between actors and a set of collaborative objects), and subsequently, for the validation of the functional requirements (i.e. blueprint of white-box test).
Use case driven approach provides an traceable links for project tracking in which the key development activities such as the use cases implemented, tested, and delivered fulfilling the goals and objectives from the user point of views.

A Use Case diagram can be developed by following the steps below.

Identify the Actors (role of users) of the system.
For each category of users, identify all roles played by the users relevant to the system.
Identify what are the users required the system to be performed to achieve these goals.
Create use cases for every goal.
Structure the use cases.
Prioritize, review, estimate and validate the users.