Choosing between agile versus plan driven approach

Increasingly, I keep hearing references like the challenges and benefits to waterfall approach versus agile approach to software development. Whether these are software developers, testers, technical operations, project management, or sales & marketing professionals, the underlying theme is that software development life cycle (SDLC) has become synonymous with waterfall development but agile is not. Focusing on the core principles of agile, primarily ‘working software versus comprehensive documentation’, isn’t agile approach also developing a software? Aren’t the concepts of planning at various layers, such as daily, iteration or sprint, and release, to iteratively develop incremental software enhancements part of a life cycle for software development? So, where is the huge disconnect?

The challenge is not in the approaches but in people’s incorrect assumptions in thinking what the original SDLC proposition was and equating it to waterfall. In fact, in a recent meeting that I attended in PMI Mass chapter, many participants didn’t relate to the original author of SDLC, Winston Royce’s seminal proposition in 1970 who himself related to the challenges promoting incremental and iterative approach and the increasing involvement from project management in software development. Practitioners therefore created a non-existent and non-functional theory of waterfall embedded with the assumptions below that are challenged by my scholarly publication (Rajagopalan, 2014). 

1.       Linear approach to software development with no feedback
2.       Big upfront requirements gathering
3.       Gathering requirements upfront saves cost
4.       Analysis follows requirements followed by design
5.       Project Management is not part of software development
6.       High degree of documentation needed before starting work
7.       Customer sees work after all the work is developed and tested
8.       Testers need not be involved early

Therefore, I will deviate from using the word, “waterfall” or “traditional” approach and recommend using the “plan driven development” using the rapid application development and fundamental project management principles. Basically, the requirements for the choice of agile or plan driven approach to software development lies in the problem being solved. 

If the challenge is to build a mission critical application controlling the amount of x-ray radiation that will be discharged by a software application, then, a plan driven approach may be a better fit because of the certainty in requirements that can be reasonably predicted, and the amount risk involved in doing it incorrectly without impacting the profit margin. On the other hand, if the requirements are not certain and the complexity is not high where the functionality is possible to release in an iterative fashion such as a new mobile application or responsive website for student enrollment in a college, then, agile may be a better candidate. 

So, instead of choosing the methodology and solving the problem using the methodology, the methodology must be chosen based on the problem solved!

Thoughts? 

References

Rajagopalan, S. (2014). Review of the myths on original software development model. International Journal of Software Engineering & Applications, 5(16), 103-111. Retrieved from http://airccse.org/journal/ijsea/papers/5614ijsea07.pdf