Latent Defect In Software Testing

September 05, 2019

Testers, while ensuring the quality and performance of the product come across various defects. Some are easy to identify while others are masked or hidden in the product and require intensive measures to be uncovered. Among these defects, there is an unusual one, that remains hidden until the circumstances reveal it and it becomes a hindrance in the on-going process. This type of defect is known as Latent Defect and is commonly observed in software testing. So, let us understand what latent defect connotes to and the impact it has on the software product, before as well as after the delivery.

What is Latent Defect in Software Testing?

One of the unusual defects found during software testing, Latent Defect is an error that hasn’t occurred yet, and that can lead to failure whenever an accurate set of conditions are not fulfilled. It is a systematic flaw that accompanies the software during the production process and even passes the initial testing, including the pre-production testing and extended use.

Present in the system for a long time, latent defect is uncovered by the users in the real-world environment, when a particular task is performed in the absence of regular scenarios or due to an unusual or rare set of conditions.

Latent Defect Example

February has 28 days, except in a leap year. The system might is not able to consider the leap year or an extra day in February, which results in a latent defect.

Signs of Latent Defect

As stated earlier, defects in software are of various types, which makes it crucial for the team to classify latent defects from other them. Therefore, while testing the software, testers need to look out for the following signs, as they can help them differentiate a normal defect from the latent ones. These signs are:

Remains after the production of the product.
Passes all types of tests.
It occurs in triggered scenarios.
It is extremely difficult to identify.
Usually identified after the release of the product, by the user.

How to Identify & Resolve Latent Defects?

Though latent defect is quite challenging to identify, yet it isn’t impossible, and can be achieved through:

Inspection: Constant inspection by the tester or the user, after the product is deployed, can help identify as well as resolve these defects.
Exhaustive Testing: Even though it is impossible to perform "exhaustive testing", testers need to ensure all scenarios are tested at least once so that they can reduce the possibilities of hidden latent defects.

Key Points:

If ignored, it can create major issues in the future.
It can cause data corruption and misreporting.
Can exist in the system for one or more versions.
It’s among the three unusual defects found during testing:

Latent Testing.
Masked Testing.
Defect Cascading.

Latent Defect vs Masked Defect:

Even though both latent and masked defects are present in the system for a long time and are non-identified, yet they are vastly different from one another. It is to specify these differences, here is a comparison of the two:

Latent Defect	Masked Defect
1. Latent defect remains unidentified because the accurate set of inputs or conditions were never met.	1. Marked defect remains unidentified as another defect has prevented that part of the code from being executed.
2. It occurs in triggered scenarios, in the production environment.	2. This occurs after the hidden defect is identified.
3. Identification of these leads to the identification of masked defects.	3. It is covered or masked by another defect, like latent defects.

To learn more about "Masked Defect", click here.

Latent Defect Infographics

Conclusion:

Latent defects are among those important defects that are present in the software and can impact its functionality over time. Therefore, it is crucial for the team of testers to take all the necessary measures to ensure they are identified and resolved before the product is delivered to the end-user.