Empower

Welcome to the September 2022 issue of Empower, the periodic newsletter of the IsDB-BISEW IT Scholarship Programme. This edition includes the following topics of note:

• UML Diagrams: A Comprehensive Overview

• Snapshot of Job Placement of IT Scholarship Programme in 2022

UML Diagrams: A Comprehensive Overview

This comprehensive guide to UML Diagrams explains what is a UML Diagram, its uses and types:

The Unified Modelling Language (UML) is a general-purpose, developmental modelling language in the field of software engineering that is intended to provide a standard way to visualize the design of a system.

The creation of UML was originally motivated by the desire to standardize disparate notational systems and approaches to software design. It was developed at Rational Software in 1994–1995, with further development led by them through 1996.

In 1997, UML was adopted as a standard by the Object Management Group (OMG), and has been managed by this organization ever since. In 2005, UML was also published by the International Organization for Standardization (ISO) as an approved ISO standard.[2] Since then the standard has been periodically revised to cover the latest revision of UML.

A UML diagram can be helpful to businesses and other individuals who wish to simplify the development process. Diagrams allow individuals to brainstorm ideas, make plans, and communicate.

UML Diagram Guide

Unified Modelling Language is the term for UML. It defines a specific architecture, design, and implementation of a complex software system. UML is a visual representation of a software program that uses a series of diagrams. By using standard engineering practices that have proved effective over the years, large and complex systems can be effectively modelled.

In UML diagrams, a general-purpose language, a model is used to communicate software design. It simplifies communication and allows you to visualize the model. Software systems have many subcomponents and thousands of lines of code, making it difficult to keep track of their relationships. Unified Modelling Language diagrams enable you to see these relationships.

What are UML Diagrams

Unified Modelling Language diagrams serve to describe, analyze, discover, and test a system’s characteristics, behaviors, and other features.

A UML diagram is created before, during, and after coding an application to better understand the roles, activities, and workflows involved in the application. Using the diagram, possible errors in the design can be easily detected, resulting in a better-quality final product.

Unified Modelling Language Usage

UML diagrams are widely used in software engineering and other business processes where model-based decisions are useful.

When used in these processes, UML diagrams contribute in two main ways:

• Forward design: Coding the software application occurs after the modeling and design have been completed. When creating a new system, a developer uses forward design to think about what they want to achieve.
• Backward design: Modelling occurs after the code has been written, and UML diagrams serve as an important tool to document the project’s workflow. The developer can then analyse the project development, in reality, to see where improvements can be made to make it better in the future.

It provides a visual representation of many aspects of a project and identifies who is responsible for which part of it. It can be prepared before or after coding.

UML Diagram Symbols

Each type of UML diagram uses different symbols. The class diagram represents the attributes of a class in UML diagrams and is a common type.

In the UML class diagram, a class’s responsibilities, operations, and attributes are represented by segments.

Notations of UML class members indicate whether members are visible, as shown below:

+ Public

- Private

# Protected

/ Derived

~ Package

Relationships between components can also be shown with lines:

• An empty arrowhead denotes generalization and inheritance. A filled diamond indicates composition.
• Diamonds indicate aggregates, whereas dashed lines with arrows represent dependencies.
• The properties of a dependency can be specified with << >>. An arrow with a number and a * denotes multiplicity.

The following diagram shows various relationship arrows:

Most activity diagrams show symbols representing activity types, states, and an initial state as well as a final state. In most control flow diagrams, arrows depict control flow, and dashed arrows represent object flow.

Users can identify actors and use cases using Use Case diagrams.

Types of UML Diagrams

There are 14 types of Unified Modelling Language diagrams. These diagrams are divided into behavioural and structural diagrams according to their functions. Not all diagrams shall be shown in this article. Only the most often used diagrams shall be described here.

• Structural Diagrams: These diagrams describe the structure or statics of a system. Among the Structure Diagrams are the Component diagram, Object diagram, Package diagram, Class diagram, and Deployment diagram.
• Behaviour Diagrams: Behavioural UML Diagram examples depict how the system behaves dynamically. A behaviour diagram includes Use Case diagrams, State diagrams, Activity diagrams, Interaction Overview diagrams, Sequence diagrams, State diagrams, Communication diagrams, and Timing diagrams,

Structural Diagrams

This system shows the different objects in a structured way, or it can be said that the different objects are displayed contextually.

#1) UML Class Diagram

A class diagram is the backbone of any object-oriented solution since it shows the hierarchy of a system. There is a relationship between the attribute, object, operation, and even classes.

The class is further divided into three parts:

• The top part consists of the name.
• The bottom part consists of the operations.
• The middle part consists of the attributes.

These classes are grouped to create a class diagram. The below UML class diagram example shows the Organization structure.

#2) Object Diagram

Like the class diagrams, the object diagram also shows the relationship between the objects used in the real world. A diagram can explain the relationship between the objects with great precision since the data is contained in the objects.

However, the object diagram is more specific than the class diagram. It will show the complete view of the structure in the customized system at a specific time.

#3) Component Diagrams

The component structure diagram shows the relationships between different software system components. This complex system contains several components and is used when working with complexities alone.

The component even communicates with each other with the help of interfaces, as the interface is connected with the connectors that help them communicate.

Below is a component diagram for a Library management system:

#4) Deployment Diagram

The deployment diagrams show the hardware of the system and the software in that hardware. A graph can be useful when a software solution is distributed across multiple machines and has a unique configuration. It shows where the pieces of the solution are interconnected.

Below is an example of a deployment diagram for hospital management software:

Behavioural Diagram

A behavioural diagram depicts activities and interactions that will occur within the system. Understanding the relationship between these objects helps in constructing a functional system.

#1) Activity Diagrams

Activity diagrams indicate the workflow of the business graphically. It is an easier way to explain to others. It can describe the operational workflow or business workflow in a system. These activity diagrams are also an alternative to state machine diagrams. It encompasses both organizational processes and computations, along with the data flows connected to related activities.

Below is the Activity diagram for online shopping:

#2) Sequence Diagrams

Sequence diagrams represent how objects will interact with each other, in what order, and as a result, what is taking place. Interactions are represented by arrows, while processes are represented vertically.

A sequence of messages is exchanged between individuals and used to determine the functionality of the scenario.

Below is the Sequence diagram for an Online exam system:

#3) Use Case Diagrams

In the Unified Modelling Language (UML), a use case diagram can summarize the details of your system's users (also known as actors) and their interactions with the system. To build one, you'll use a set of specialized symbols and connectors. An effective use case diagram can help your team discuss and represent:

• Scenarios in which your system or application interacts with people, organizations, or external systems
• Goals that your system or application helps those entities (known as actors) achieve
• The scope of your system.

A website use case diagram is shown below.

Snapshot of Job Placement of IT Scholarship Programme in 2022

The year 2022 saw the beginning of the recovery of the IT job sector from the impact of the COVID-19 pandemic. Placement has gained momentum and is set to surpass the numbers achieved in 2021. Placement figures for the first nine months of this year are shown below.

Placement Data (as of 30 September – 2022)

Some of the Positions in which IsDB-BISEW Graduates were Recruited in 2022

A Sample List of Organizations which have Employed our Graduates in IT Positions

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