# ✅ What is Boundary Value Analysis (BVA)?

**URL:** <https://forum.nocodework.com/t/what-is-boundary-value-analysis-bva/240>\
**Category:** General\
**Created:** [August 1, 2025, 12:31pm UTC](https://forum.nocodework.com/t/what-is-boundary-value-analysis-bva/240 "2025-08-01T12:31:10Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Akash](https://avatars.discourse-cdn.com/v4/letter/a/a5b964/32.png) [@Akash](https://forum.nocodework.com/u/Akash)\
**Post date:** [August 1, 2025, 12:31pm UTC](https://forum.nocodework.com/t/what-is-boundary-value-analysis-bva/240/1 "2025-08-01T12:31:10Z")

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**Boundary Value Analysis** is a **black-box testing technique** where test cases are designed to include **values at the edges of input ranges**.

> 🧠 **Why?**  
> Most defects tend to occur at the boundaries of input domains rather than in the center. BVA helps catch **off-by-one errors** or logic issues near limits.

## 📘 **Basic Principle:**

If an input field accepts a value from **X to Y** , then test the values:

- Just below the minimum: `X - 1` ❌

- At the minimum: `X` ✅

- Just above the minimum: `X + 1` ✅

- Just below the maximum: `Y - 1` ✅

- At the maximum: `Y` ✅

- Just above the maximum: `Y + 1` ❌

## 🧠 **Example Scenario**

**Requirement:**  
A user must enter an age between **18 and 60** (inclusive).

Input Range: 18 – 60

| **Test Case ID** | **Input Value** | **Expected Result** | **Reason** |
| --- | --- | --- | --- |
| TC001 | 17 | Invalid | Just below min value |
| TC002 | 18 | Valid | Lower boundary value |
| TC003 | 19 | Valid | Just above lower boundary |
| TC004 | 59 | Valid | Just below upper boundary |
| TC005 | 60 | Valid | Upper boundary value |
| TC006 | 61 | Invalid | Just above max value |

## 🧪 **Where is BVA used?**

- Form validation (age, amount, date, quantity)

- Range validation

- Input fields with numeric limits

- Sliders, pagination, or scrollbars

- API validations (min/max length, numeric boundaries)

✅ **Summary** :

| Feature | Value |
| --- | --- |
| Type | Black-box Testing Technique |
| Focus | Input boundaries |
| Goal | Catch edge case bugs |
| Test Count | Usually 6 test cases per input field |