Testability in simple terms can be defined as the extent of ease with which a system can be tested. The ISO defines testability as “attributes of software that bear on the effort needed to validate the software product.”
Any project you take or own, testability of the software that is being created or amended is a decisive factor in the time and cost of testing. At times the management decides to drop a few parts or phases of testing which ultimately results in a low quality product and also the product is not able to stand in competition in the market.
Like we all know that testing has no end rather it is a never ending task. It is something that needs to be up-to-date with the user’s preferences; it is a part of the life span of any software. And a wholesome truth is that software keeps altering, considering its upgradation to meet the demands of the customers and to stand in the competitive market. The new dimensions of software testing can also serve as a bridge for an effective testability.
In this purview, dedication towards testability of a system gives return over its entire life span. Testability is valuable and is a quality characteristic of a software system, along with all-time classics like functionality, security, and performance.
Software Testability Measurement
Software testability measurement refers to the activities and methods that study, analyze, and measure software testability during a software product life cycle. Once software is implemented, it is essential to make an assessment to finalise which software components are likely to be more difficult and time-consuming in testing due to their poor component testability. If such a measure could be applied at the beginning of a software testing phase, much more effective testing resources allocation and prioritizing could be possible. The objective of software testing is to make sure that the given software product meets the mentioned requirements by validating the function and nonfunctional requirements to uncover as many program defects as possible during a software test process. Unlike software testing, the major objective of software testability measurement is to find out which software components are poor in quality, and where faults can hide from software testing.
Testability is essential because:
- Sooner is better
- Higher testability – Better results, same cost
- Lower testability – Fewer weak results, same cost
There are numerous measures that can be taken to enhance testability as listed below:
- Transparency: Know in an out about the system, what it does and what it is supposed to do. Have a crystal clear understanding.
- Updated system documentation
- Comprehensive well-structured code
- Clarity in software requirements
- Isolation: Try techniques and mention codes by which parts of the system can be tested in isolation. Document each concern separately and make the results visible.
- Go for a test environment simulation: Strike a balance between representativeness and flexibility in favour of the system and give in suggestions wherein you can opt for automated tests.
The aforesaid measures may not be in the hit list of any manager or product owner but certainly they enhance the offerings of both the developers and the testers hence more efficient results. This helps in creating a better quality product and proves cost effective too. Testability establishes the boundary to which the jeopardy of costly or hazardous bugs can be abridged to an acceptable level.
