What is -: Defect clustering in software testing means most of the bugs detected and found in small modules. When product is in development process then development is divided into number of phases and modules against the user specified requirement.
During software testing, defects are found and detected during pre-release or responsible for operational failure. For pesticide paradox
Sometimes a small functionality may produce many defect when compare with bigger functionality because of poor requirement and lack of experience.
Defect Clustering is based on the Pareto principle, i.e 80-20 rule, where it is stated that approximately 80% of the problems are caused by 20% of the modules in product development.
It focuses on most error prone area. Errors are occurs due to complex code and tricky design.
Test designers often use this information for the risk assessments for planning the tests, and will focus on these known areas that may also be called as Hotspots.
During the software testing in SDLC of E-Commerce, defects are found and analyzed. The distribution of defects are not across the application but rather centralized in limited sections of the application like product details, reviews, price, sort, filter, search and home page. As consider the small modules most of defect can be found search, product details and reviews.