The approach to software development methodology saw the need for something different a few decades ago. The old approach of the well known Waterfall methodology was seen as to restrictive to take full advantage of the type of workers that create software programs.
Since the linear approach to software development methodology, like the waterfall, had so many pitfalls, other approaches were examined. This included the prototyping and cyclic methodologies. Each of these was an improvement but still very structured and restrictive.
What was needed was an iterative approach for a software development methodology to follow. This came into being in 2001 with the use of the Agile methodology. This is a combination of both iterative and incremental methodologies that was found to best suit the type of workers that were in this industry.
This type of worker that was needed usually worked best alone and isolated from others. They find Inspiration and ideas that come in spurts so a less structured approach to the software development methodology that allows for this is the best one to use.
This new software development methodology has a very important requirement that must be adhered to and that is self discipline by the workers. Because it is very rare that only one person develops an entire program by themselves, deadlines must be made and kept so the cross functioning teams can coordinate their programs.
The approach for the modern software development methodology will not work in most other industries, but it is highly successful in the IT industry. Many of the programmers work odd hours to not only meet deadlines but because that is when the solution is found in their minds. This is a creative task that must be given freedom for it to be done efficiently and productively.
By utilizing a software development methodology to develop your program, you allow the creation of something new that comes from the mind of a unique set of individuals. This new approach is what was necessary for the job to be accomplished. Just like with many problems, a new solution was needed.