System And Software Development Life Cycle (SDLC) : MCQs & PYQs with Explanation

Option C

A Software Development Life Cycle (SDLC) model defines the structured process followed to develop software. It describes how software moves from the requirement stage to deployment and maintenance.
The Waterfall Model is one of the earliest and most well-known SDLC models. It follows a linear and sequential approach, where each phase must be completed before moving to the next phase.
The typical phases in the Waterfall Model are:
1.  Requirement Analysis.
2.  System Design.
3.  Implementation (Coding).
4.  Testing.
5.  Deployment.
6.  Maintenance.
Due to its rigid structure, it is not suitable for accommodating changes easily once a phase is completed.

• It is not flexible for changes.
• Any modification requires going back to the earlier stages, which is costly and time-consuming.
• It works well only when requirements are very clear and stable.

Option A

In the Spiral Model, software is developed through a series of iterations or cycles. Each cycle adds more functionality to the software, resulting in incremental releases. The model combines the iterative nature of development with strong emphasis on risk analysis and management.
A Sequential Model, such as the traditional Waterfall Model, follows development phases in a largely sequential order. It does not primarily describe software development as a series of incremental releases.

Option A

The Spiral Model is a risk-driven software development model that follows iterative cycles or loops. Each loop includes planning, risk analysis, development, and evaluation. These cycles continue throughout the life of the software.
The spiral does not stop after a fixed number of loops or after a specific phase like testing or release. Instead, it continues even after deployment for maintenance and improvements.
The model finally ends only when the software is no longer in use and is retired.

Option C

Option A

The Preliminary Investigation phase is the first step in the System Development Life Cycle (SDLC). This phase acts like a screening process to decide if a project should move forward. During this phase, the system analyst evaluates:

• New project requests.
• The purpose of the project.
• Problems in the current system.
• Whether the project is feasible.
• Whether it should be accepted, modified, or rejected.

Option D

The Spiral Model integrates the structured nature of Waterfall with the risk assessment and iterative approach of Prototyping.

Option B

The Cleanroom software engineering strategy focuses on developing software with high reliability and zero defects by using formal methods, correctness verification, and statistical quality control. It follows an Incremental Development Approach, where the system is built and delivered in small, verified increments.

Option C

A generic process framework in software engineering consists of five main framework activities, usually, Communication, Planning, Modeling, Construction, Deployment. When these activities are carried out one after another in a strict sequence, it is called a Linear Process Flow.
The linear process flow means, no overlaps, one activity must finish before the next begins, follows a straight, step-by-step path. This is very similar to the Waterfall Model.

Option D

In Software Engineering, there are four fundamental activities that guide the development and maintenance of software systems.

Option C

When developing a new system, it is often helpful to build a quick, small, and low-cost version of the actual system first. This early version is called a Prototype. 
A prototype is  working model of the system. It is created with the intention of being modified, refined, or replaced later by a full-scale, fully operational system.

Note:

In system or software development, building the full system at once can be costly and risky if requirements are unclear. To address this, a Prototype is made as an early version that may not have all features but represents essential aspects of the system.