Frequently Asked Questions on Software Engineering
Question 1
a) Define the Software Development Life Cycle (SDLC). List its phases with a brief explanation.
The Software Development Life Cycle (SDLC) is a structured process used by software development teams to design, develop, test, and deploy high-quality software. It provides a framework for project management and control.
The typical phases of the SDLC are:
Requirements Gathering and Analysis: This initial phase involves collecting and analyzing all the functional and non-functional requirements from the client or stakeholders.
Design: The development team creates a blueprint or a detailed design of the software, including its architecture, user interface, and data model.
Implementation/Coding: Developers write the actual code for the software based on the design specifications.
Testing: The software is rigorously tested to identify and fix defects, ensuring it meets the specified requirements.
Deployment: The completed software is released to the end-users or deployed in a production environment.
Maintenance: This ongoing phase involves providing support, fixing bugs, and implementing enhancements to the software after it has been deployed.
Question 2
a) Compare Agile Development with the traditional Waterfall approach.
| Feature | Agile Development | Waterfall Model |
| Approach | Incremental and iterative. | Linear and sequential. |
| Flexibility | Highly flexible and adaptable to changes. | Rigid; difficult and costly to change requirements once a phase is complete. |
| Working Product | Delivers a working product early and frequently. | A working product is only available at the end of the project. |
| Customer Involvement | High and continuous involvement. | Limited involvement, typically at the beginning and end. |
| Documentation | Minimal, focusing on working software. | Extensive and detailed documentation. |
| Risk | Risks are handled iteratively throughout the project. | Risks are often identified late in the process. |
b) Explain the Spiral Model and compare it with the Incremental Model.
The Spiral Model combines the iterative nature of prototyping with the systematic, controlled aspects of the Waterfall model. It is a risk-driven approach where a project spirals outwards from a central point, with each loop representing a phase of the development process. Each loop consists of four main activities: planning, risk analysis, engineering, and evaluation.
Spiral Model
Focus: Primarily focused on risk management,
Structure: A series of iterative loops, with risk analysis at the heart of each loop.
Best For: Large, high-risk projects.
Incremental Model
Focus: Primarily focused on delivering working functionality in small, manageable increments.
Structure: A series of mini-Waterfalls, each producing a new increment of the software.
Best For: Projects with well-defined requirements that can be delivered in parts.
Question 3
a) Paint the role of Requirements Engineering in the process of Software Engineering.
Requirements Engineering is a crucial discipline in software engineering that involves defining, documenting, and maintaining software requirements.
- It acts as the bridge between the customer's needs and the technical implementation.
- Its key role is to ensure that the software being developed will actually meet the needs of the end-users and stakeholders.
- Without a strong requirements engineering process, projects are likely to fail or deliver a product that doesn't solve the intended problem.
b) Paraphrase Requirement Analysis. What are functional and non-functional requirements?
Requirement Analysis is the process of studying and refining the requirements gathered from stakeholders. It involves breaking down high-level user needs into detailed, specific, and unambiguous software requirements.
Functional Requirements: These describe what the system must do. They are specific functions or behaviors of the software. For example, "The system shall allow users to log in with a username and password."
Non-Functional Requirements: These describe how the system should perform its functions. They relate to quality attributes of the system. Examples include performance (e.g., "The system shall load a page in less than 2 seconds"), security, usability, and reliability.
Question 4
a) Journalize the structure of a Software Requirements Document.
A Software Requirements Document (SRD), also known as a Software Requirements Specification (SRS), is a comprehensive description of the software to be developed. A typical structure includes:
Introduction: Provides an overview of the document, its purpose, and the scope of the project.
Overall Description: Describes the project's background, context, and key features from a high-level perspective.
Specific Requirements: The core of the document, detailing all functional and non-functional requirements. This section is often organized into subsections for clarity.
Appendices: Includes supporting information such as glossaries, diagrams, and references.
b) Express in detail the data model and object model of software engineering.
Data Model: The data model describes the structure of the data that the software will use and manage. It defines the relationships between different data elements. Examples include entity-relationship diagrams (ERDs) that show entities, attributes, and their relationships. A good data model ensures data integrity and consistency.
Object Model: The object model represents the system as a collection of interacting objects. It uses concepts like classes, objects, attributes (data), and methods (functions). It is the foundation of object-oriented programming and helps in understanding the system's structure and behavior through classes and their interactions.
Question 5
a) Define software architecture. What are the key characteristics of good architecture?
Software architecture is the fundamental organization of a software system. It defines the system's components, their external properties, and the relationships among them. It is the blueprint that guides the entire development process.
Key characteristics of a good software architecture include:
Modularity: The system is divided into independent, manageable modules.
Scalability: The architecture can handle increased load and growth.
Maintainability: The system is easy to modify and update.
Reusability: Components can be reused in different parts of the system or in other projects.
Flexibility: The system can be easily adapted to new requirements.
b) Differentiate between monolithic and microservices architecture.
| Feature | Monolithic Architecture | Microservices Architecture |
| Structure | A single, unified application. | A collection of small, independent services. |
| Deployment | The entire application must be deployed together. | Each service can be deployed independently. |
| Development | All components are developed within a single codebase. | Services are developed by small teams, often using different technologies. |
| Scalability | Scaled as a single unit (vertical scaling). | Each service can be scaled independently based on demand. |
| Failure | A failure in one part of the application can affect the entire system. | A failure in one service is isolated and does not affect the others. |
Question 6
a) Define software reusability. Explain its advantages and challenges.
Software reusability is the practice of using existing software components (such as code, modules, or designs) to build new applications. It is a fundamental principle of software engineering aimed at reducing development time and effort.
Advantages:
Faster Development: Reusing components saves time by not having to write new code from scratch.
Increased Quality: Reused components have been tested and are often more reliable and stable.
Reduced Cost: Saves on development and testing costs.
Challenges:
Finding Reusable Components: It can be difficult to find a component that fits the new project's specific needs.
Integration Issues: Integrating a reused component into a new system can be complex.
Lack of Documentation: Reused components may lack proper documentation, making them difficult to understand and use.
b) Express your view on Component-Based Software Engineering.
Component-Based Software Engineering (CBSE) is a development paradigm that focuses on creating software systems by integrating pre-existing, independently developed components. I believe it is a highly effective approach that promotes efficiency and quality. By building systems from modular, reusable parts, CBSE allows for faster development cycles and greater reliability. The key strength of CBSE is its ability to create a system from "off-the-shelf" components, much like building a house from prefabricated parts. This approach, when implemented correctly with well-defined interfaces and robust components, can significantly reduce complexity and maintenance effort. However, its success is dependent on the availability of a wide range of high-quality components and a robust framework for their integration.
