Comparison Between Agile and Traditional Software Development Methodologies
The early software development methodologies were limited to “code and fix” with little long-term planning, which worked fine for a small set of systems, but as the systems grew they became susceptible to bugs and were harder to run efficiently. Newer methodologies brought planning and discipline to the software development process, to make software development more efficient and flexible.
The advancement of technology and greater market competition added different sets of approaches to software development methodologies. Some companies over the years have introduced their own set of customized methodologies for developing their software, but the majority of worldwide companies follow two kinds of methodologies: heavyweights and lightweight.
The traditional “heavyweight” methodologies are more structured – is process and tool oriented, and follow a predictable path, requiring comprehensive and detailed documentation. Some of the popular traditional methodologies are Waterfall, Unified Process, and Spiral.
These methodologies are based on a sequential series of steps in which work begins with the elicitation and detailed documentation of overall requirements, followed by architectural and high-level design development and with checkpoints & deliverables at each phase. Due to a long set of processes and a relatively inflexible approach, this methodology got the name of heavyweight.
The newer “lightweight” methodology also known as “agile” modeling is a set of values or philosophies. Agile exposes organizational dysfunction. Unlike traditional methods, agile methodologies embrace iterations rather than phases. Agile employs short iterative cycles, small/short releases, simple design, refactoring continuous integration, and relying on tacit knowledge within a team as opposed to documentation. Some of the popular agile methods are Extreme Programming, Scrum, Lean, Kanban, Dynamic System Development Method, Feature Driven Development, and Adaptive Software Development.
The key difference between heavyweight and agile methodologies is the adaptability factor. In an agile methodology, if any major change is required, the team doesn’t freeze its work process; rather it determines how to better handle changes that occur throughout the project. The verification process in the agile method occurs much earlier in the development process. On the other hand, heavyweight methods freeze product requirements and disallow change. It implements a predictive process and relies on defining and documenting a stable set of requirements at the beginning of a project.
The agile model delivers a working version of the product and direct user involvement in the development process is very early compared to traditional methodologies. The testing cycle for Agile is continuous and comparatively short to traditional methods because testing is done parallel with development. Most traditional models are very rigid and don’t entertain changes and are relatively less flexible than the Agile model. Because of all these advantages, Agile has a comprehensive response to most of the challenges organizations face in a rapidly changing, competitive global market.
