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Age Testing

What is Age Testing?

It is a testing technique that evaluates a system's ability to perform in the future and usually carried out by test teams. As the system gets older, how significantly the performance might drop is what is being measured in Age Testing.

Let us also understand the concept of Defect Age. It is measured in terms of two parameters:

1. Phases
2. Time 

Defect Age - Phases:

Defect age in phases is defined as the difference between defect injection phase and defect detection phase.


1. 'defect injection phase' is the phase of the software development life cycle when the defect was introduced.

2. 'defect detection phase' is the phase of the software development life cycle when the defect was pinpointed.


Defect Age in Phase = Defect Detection Phase - Defect Injection Phase


Consider, the SDLC Methodology that we have adopted has the following phases:

1. Requirements Development

2. Design

3. Coding

4. Unit Testing

5. Integration Testing

6. System Testing

7. Acceptance Testing, and if a defect is identified in Unit Testing (4) and the defect was introduced in Design stage (2) of the Development, then Defect Age is (4)-(2) = 2.

Defect Age - Time:

Defect age is defined as the time difference between defect detected date and the current date, provided the defect is still said to be open.


1. Defects are in "Open" and "Assigned" Status and NOT just in "New" Status.

2. Defects that are in "Closed" due to "non-reproducible" or "duplicate" are NOT considered.

3. Difference in days or hours is calculated, from the defect open date and current date.


Defect Age in Time = Defect Fix Date (OR) Current Date - Defect Detection Date


If a defect was detected on 05/05/2013 11:30:00 AM and closed on 23/05/2013 12:00:00 PM, the Defect Age would be calculated as follows.

Defect Age in Days = 05/05/2013 11:30:00 AM - 23/05/2013 12:00:00 PM
Defect Age in Days = 19 days


For assessing the effectiveness of each phase and any review/testing activities, lesser the defect age, better the effectiveness.