Smoke Testing vs Sanity Testing: An Explanation with Examples

To the casual observer, all software testing and Quality Assurance (QA) seem to be created equal.

Yet, to those engrossed in the profession, there are so many different flavors, or types, of software testing that can be used to evaluate the performance and reliability of a design.

However, knowing where and when to deploy each type of software testing is key. And it begins with knowing the ins-and-outs of each type so they can be used at the right time.

Two types, smoke testing and sanity testing, can be particularly useful in stress testing software during development, but hard to difficult to distinguish from one another. 

Here’s what you need to know about each method, their strengths, and use cases.

Smoke Testing: What You Need to Know

Smoke testing is more of a preliminary assessment method designed to verify whether the core functionalities of a software system are in place and are operational. Its primary aim is to identify significant issues early in the development cycle as possible, thus preventing further complications down the line that could result in costly rework.

Characteristics

• Scope: Deployed broadly across the entire system or application.
• Frequency: Often executed after every new build or release to ensure basic stability.
• Execution Speed: Intended to be deployed quickly, focusing on essential functionalities.

Examples:

Testing login functionality in a web application

An e-commerce website needs to update its payment processing system. After implementing these changes, smoke testing would involve quickly navigating through the checkout process to ensure the website remains accessible and functional. If the website crashes during this process, indicating a critical fault, developers are alerted to address the issue before proceeding with more detailed testing.

Verifying database connectivity in a system

A desktop application was designed to calculate taxes, billing, and salaries for a business. If the application incorrectly calculates basic formulas smoke testing would stop further testing until this fundamental error is corrected. 

Sanity Testing: What You Need to Know

Sanity testing is a targeted evaluation of specific functionalities or components following minor modifications or bug fixes. This type of testing confirms that recent changes have not adversely affected the system's behavior.

Characteristics

• Scope: Concentrated on particular features or affected modules.
• Frequency: Conducted after minor adjustments or corrections to ensure that the changes work as intended.
• Execution Speed: Provides a more detailed examination compared to smoke testing, but is less extensive than full regression testing.

Examples:

Testing new user interface (UI) elements added

When new UI elements are added to an existing feature in a software application, sanity testing would focus on verifying that these new elements integrate seamlessly with the rest of the feature. This might involve checking that buttons, menus, or other interactive elements function correctly and do not introduce new errors or disrupt existing functionality.

Validating performance improvements in a module

After modifying workflow elements in a module, sanity testing could validate performance improvements. For instance, if a page that usually loaded slowly was optimized, sanity testing would confirm that the page now loads faster without sacrificing functionality or introducing new issues.

Head-to-Head: Smoke Testing vs. Sanity Testing

Fortunately, when it comes to QA, it doesn’t have to be an either-or situation: teams can use both methods if they need them. Here is a quick run down of the key aspects of the two methods:

Bringing it All Together

The main distinctions between smoke testing and sanity testing lies in their scope, execution time, and frequency. While smoke testing provides a broad overview of the system's stability post-builds, sanity testing offers a deeper dive into specific functionalities post-changes. 

However, both play crucial roles in the QA process, ensuring that software products meet the required standards of quality and reliability. 

Want to explore how TestMonitor’s  comprehensive test management platform can empower your QA team to efficiently manage not only smoke testing and sanity testing processes, but your end-to-end process? 

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