Software Requirements Specification (SRS) for Car Loan EMI Calculator

Introduction

Purpose:

The purpose of this document is to outline the requirements for the development of a Car Loan EMI Calculator application. This application estimates monthly EMIs for car loans, considering the principal and interest components, to assist users in planning their car loan repayments.

Scope:

The Car Loan EMI Calculator will provide users with a tool to estimate their monthly car loan repayments, facilitating informed decision-making about car loan affordability. Users will input details such as loan amount, interest rate, tenure, and any additional parameters, and the system will calculate and display the monthly EMIs.

System Overview

System Description:

The Car Loan EMI Calculator will be a web-based application accessible through a browser. It aims to provide users with a user-friendly interface to input car loan details and receive accurate EMI calculations.

System Architecture:

The application will follow a client-server architecture, with the client being the web browser and the server handling the EMI calculation logic.

Functional Requirements

Use Cases:

Estimate Car Loan EMI:

• Users can input details such as car loan amount, interest rate, loan tenure, and any additional parameters (e.g., prepayments).
• The system will calculate and display the monthly EMI, including principal and interest components.

Functional Requirements:

Input:

The system shall accept the following input:

• Car Loan Amount (in INR)
• Interest Rate (in percentage)
• Loan Tenure (in months or years)
• Additional Parameters (e.g., prepayments, if any)

Calculation:

• The system shall use the standard EMI formula to calculate the monthly EMI, including principal and interest components.

Output:

• The system shall display the calculated monthly EMI, principal component, and interest component to the user.

Non-Functional Requirements:

• The system should provide a response time of under 2 seconds.
• The application should be accessible on common web browsers (Chrome, Firefox, Safari).

External Interface Requirements

User Interfaces:

• The user interface shall include input fields for car loan amount, interest rate, loan tenure, and additional parameters, along with a “Calculate” button.
• The calculated monthly EMI, principal component, and interest component shall be displayed prominently.

Hardware Interfaces:

• The system should be compatible with standard computing hardware.

Software Interfaces:

• The application shall be developed using HTML, CSS, and JavaScript.
• The server-side logic can be implemented using a backend framework (e.g., Node.js, Django).

Communication Interfaces:

• The application will communicate with the server for the EMI calculation and display of results.

Performance Requirements

Response Time:

The system should respond within 2 seconds for a typical user input.

Throughput:

The application should handle at least 100 simultaneous users.

System Constraints

Regulatory Requirements:

The application should comply with relevant financial regulations.

Hardware Limitations:

The system should be compatible with devices with standard web-browsing capabilities.

Security Requirements

Authentication:

The application may not require user authentication as it’s a public tool.

Data Protection:

The system should not store or retain any user input data after the calculation.

Quality Attributes

Reliability:

The application should produce accurate results based on the provided input.

Maintainability:

The code should be well-documented for ease of maintenance.

Usability:

The user interface should be intuitive, requiring minimal guidance.

Testing Requirements

Test Cases:

Test cases should cover various car loan scenarios and additional parameters to ensure accurate EMI calculations.

Test Case 1:

• Inputs: Car Loan Amount = 8,00,000 INR, Interest Rate = 8%, Loan Tenure = 5 years.
• Expected Output: Monthly EMI ≈ 16,344 INR, Principal Component ≈ 8,00,000 INR, Interest Component ≈ 2,94,640 INR

Test Case 2:

• Inputs: Car Loan Amount = 10,00,000 INR, Interest Rate = 7.5%, Loan Tenure = 4 years.
• Expected Output: Monthly EMI ≈ 24,308 INR, Principal Component ≈ 10,00,000 INR, Interest Component ≈ 1,00,000 INR

Test Case 3:

• Inputs: Car Loan Amount = 6,00,000 INR, Interest Rate = 9%, Loan Tenure = 6 years.
• Expected Output: Monthly EMI ≈ 11,616 INR, Principal Component ≈ 6,00,000 INR, Interest Component ≈ 2,10,560 INR.

Acceptance Criteria:

The application is considered successful if it produces correct monthly EMI amounts, principal components, and interest components based on the standard EMI calculation formula.

Project Timeline

Milestones:

Design, Development, Testing, Deployment.

Development Phases:

Frontend development, Backend development, Testing, Deployment.

Glossary

EMI: Equated Monthly Installment

Database Structure

Tables:

Car_Loan_EMI_Records:

• RecordID (Primary Key, Auto-increment)
• CarLoanAmount (Decimal)
• InterestRate (Decimal)
• LoanTenure (Integer)
• AdditionalParameters (Text)
• MonthlyEMI (Decimal)
• PrincipalComponent (Decimal)
• InterestComponent (Decimal)
• CalculationDate (DateTime)

Conclusion

This extended SRS document provides a more detailed overview of the Car Loan EMI Calculator application, including the database structure and additional test cases. It should be reviewed and approved by relevant stakeholders before proceeding with the development phase.