Scott Ambler



Lean and Agile Software Development is More Successful than Waterfall

May 26, 2014



On average Lean software development strategies (think Kanban) appear to be the most effective ways of working.  Agile (think Scrum or Disciplined Agile Delivery) and Iterative (think Unified Process) approaches are statistically the same regarding success rates.  Similarly Traditional (Waterfall) and Ad-Hoc (no defined process) strategies are also statistically similar regarding success rates.  Overall, on average Lean teams enjoy a higher success rate than Agile/Iterative teams which in turn fare better than Traditional/Ad-Hoc teams.


How do we know this?  Our 2013 IT Project Success Rates Survey explored how effective the five most common software paradigms are.  The survey explored the effectiveness of these paradigms – Lean, Agile, Iterative, Ad-Hoc, and Traditional – by first asking respondents whether their organizations had such development teams and if so how successful were they.  Success was defined in terms of the success criteria being applied by their organization to the teams (see the SA+A Insight There is no Common Definition of Software Development Success).   The following infographic compares the effectiveness of the common software development paradigms:



Why is this important to you?  There is still a lot of misunderstanding about the effectiveness and validity of Agile and Lean techniques within the IT community.  Recognizing that there is a potential to improve your success rates by adopting Agile and Lean strategies over Traditional ones is an important step to helping Agile/Lean naysayers to reconsider their position.   Furthermore, they are likely to find the related SA+A Insight Modern Software Development Strategies are More Effective to be of interest.


Of course these are averages and your mileage may vary.  For more results from this survey, read the SA+A Insight Comparing Software Development Paradigms.


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