Agile-Waterfall Hybrid Best for Structural Quality According to CRASH Report Findings


For the last half-decade, a debate has raged over which project management method reigned supreme – Agile or Waterfall. To determine which held the advantage, some looked at the management techniques and fluidity with which projects were completed, others judged the debate by pointing to the structural quality of the applications being developed.

Recently, CAST released its biennial CRASH Report, which reviews the structural quality of business critical applications. This year’s CRASH report looked at application development teams utilizing the two management methods as well as those that employ a hybrid version of the two. Depending upon your view of the debate, the results will either solve it for good or add fuel to the fire.

“Across all health factors, a hybrid mix of Agile and Waterfall methods produced higher scores than either Agile or Waterfall methods alone,” said Bill Curtis, Senior Vice President and Chief Scientist for CAST, who oversees the administration of the CRASH report. “These results suggest that for business critical applications the value of agile and iterative methods is enhanced by the types of up-front architectural and design activity characterized by Waterfall methods.

Every two years, CAST sets out to review global trends in the structural quality of applications for business. The sample in this year’s report consisted of 1,316 applications, totaling approximately 706 million lines of code, that were submitted by 212 organizations in 12 industry sectors, primarily in the United States, Europe and India. Each of those lines of code is scrutinized by automated analysis and measurement to highlighting trends in five structural quality characteristics:

  • RobustnessCRASH-Agile-Waterfall
  • Performance
  • Security
  • Changeability
  • Transferability

Applications are graded on a four-point scale based on their performance in these areas, which are then averaged to achieve an overall “Total Quality Index” (TQI), which quantifies the overall health of an application. The higher the TQI, the more structurally sound the application is.

In studying the various development methods, the CRASH report found that individually, both Agile and Waterfall methods were better in all areas than no development management method. However, those businesses that used a hybrid of the two methods scored far better in terms of structural quality for robustness, security and changeability, and slightly better in performance and transferability, than businesses that used one or the other method on its own. As for overall health, both Agile and Waterfall methods had TQIs of around 3.2, while applications developed by a hybrid of the two methods had a TQI of around 3.4.

Complete results of the most recent CRASH report can be downloaded from the CAST web site at

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Jonathan Bloom
Jonathan Bloom Technology Writer & Consultant
Jonathan Bloom has been a technology writer and consultant for over 20 years. During his career, Jon has written thousands of journal and magazine articles, blogs and other materials addressing various topics within the IT sector, including software development, enterprise software, mobile, database, security, BI, SaaS/cloud, Health Care IT and Sustainable Technology.
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