QADirectory (2016) justifies the usage of waterfall model stating “Apart from other approaches to software development, top testing companies also use waterfall model for testing small projects where the requirements are simple and well-defined. Due to cascading effect from one phase to the other, this method is costs-effective, easy to use & follow, allows managerial control and departmentalization.”.
It must be the less cost and easy management that companies still opt for the waterfall approach. For large scale developments, waterfall certainly won’t produce good results. Peterson (2009) did a case study regarding the use of waterfall for large scale projects and he concluded “The results are that the most critical issues in waterfall development are related to requirements and verification. In consequence, the waterfall model is not suitable to be used in large-scale development. The comparison of the case study findings with literature shows that all issues found in literature are found in the case study. Though, the case study findings provide more detailed explanations of the issues and identified four new issues, namely 1) confusion of who implements which version of the requirements, 2) high effort for maintenance, 3) specialized competence focus and lack of confidence of people, and 4) problems in fault localization due to communication barriers.”.
Peterson, K. et al (2009) The waterfall model in large scale development. Available at: https://www.researchgate.net/publication/30498645_The_Waterfall_Model_in_Large-Scale_Development (Accessed: 5 June 2017)
QADirectory (2016) Why Top Testing Companies Tend to Use Waterfall Development Model. Available at: http://testing-companies.com/why-top-testing-companies-tend-to-use-waterfall-development-model/ (Accessed: 5 June 2017)