Application development is one of the most challenging processes for enterprises and choosing a model approach for the same is a complex decision to make. An application development model or Software Development Lifecycle Model(SDLC) is the heart of any development process. There are several models for SDLC like agile, waterfall, V-shape, iterative, spiral, etc.
The battle of agile and waterfall for the dominance over SDLC model acceptance has been a happy hunting ground for developers around the world. Developers and enterprises are looking forward to tapping into agile methods to create applications faster, secure and leaner. But, there are ardent followers of the waterfall model that are still using it as an SDLC model for application development.
What is the waterfall model?
The waterfall model is based on a waterfall-like structure of phases of any application development lifecycle. Each phase has an iterative relationship with each other that provides direct value to the end-product. Other phases are needed to be staffed and planned differently for the best utilization of program resources.
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There is a sequel dependability among the phases, which holds back the system design whenever the analysis model is still to be signed off and holds back coding if design is still to be signed off. Each development step progresses, and the design is further detailed by iteration with every preceding and succeeding step.
Due to the addition of the preliminary program design phase between requirements and analysis phase, the designer assures that the software or app will not fail because of storage, time or data flux. The waterfall model relies on documentation of every phase, with a view of building a shorter and smarter phase consisting of all the phases to ensure customer involvement in both during and after the program design phase.
What is the Agile model?
Agile techniques depend on the iterative development and a focus on iteration, communication and the reduction of resource-intensive intermediate artifacts. It combines short iterative cycles with the feature planning and dynamic prioritization. Any agility in development of apps or softwares require face-to-face interactions that can be achieved through close customer relationships.
Image Source: SDLC Models Explained
These customer relationships can help teams make decisions immediately rather than waiting for the correspondence to happen from the customer's side. Each iteration in agile methodology is an iterative product itself. They are like self-contained mini-projects with activities that span requirement analysis, design, deployment, and test.
These iterations encapsulates all the digital resources across the teams and act as a subset of the final system. The customer provides feedback based on the observations of current iterative releases and specify requirements for further iterative releases.
Enterprises hire ios developers and android developers to exploit the iterative releases across platforms prevalent in agile model. The predetermined length of an iteration serves as the deadlines for the teams.
In this SDLC model, each iteration is better known as a "Sprint". The sprint is a 30-day development iteration, where the whole process of an iterative release is carried out in 30 days. During the sprint, there is no change to be made in the metrics and parameters of a sprint and the same should be reviewed by the teams at the end of the sprint.
A wholistic comparison between Agile and Waterfall methods:
- Primary Requirements: For conventional methods like a waterfall, the major set of objectives are predictability, repeatability, and optimization. While Agile techniques focus on rapid value and rapid response to the changes.
- Scaling: Waterfall techniques are better for scaling large projects. While agile methodology is not good at scaling large projects and suits best for the smaller projects where the organizational structures of a waterfall system fails.
- Customer Relations: Agile methods works better when it comes to customer relations with a condition that customers operate in a dedicated mode with the development teams. This method risks the pitfalls of implicit knowledge, which is solved through documentation in the waterfall model.
- Planning and control: The waterfall model focuses on project management requirements like careful planning, estimation, coordination, tracking, and control. While agile methods are more focused on the results than documentation.
- Communication: Agile techniques advocate face-to-face communications and waterfall methods require explicit documented knowledge.
- Requirements of Process: The agile model does not entertain the up-front and formal requirements engineering. While the waterfall model encounters problems with rapidly changing requirements.
- Development: The waterfall model relies heavily on the infrastructure of a software or application as a part of the development sequence. While the agile model values the working software or app over documentation and emphasizes simplicity.
- Testing: The waterfall model focuses on architecture and documentation adopting conventional assurance methods that involve dynamic testing, static analysis with internal and third-party evaluation. The agile model facilitates internal design and code review that encourages developers to adopt the coding standards.
- Skill Of Customers: Agile requires dedicates, co-located and knowledgeable customers. While the waterfall model needs adequately skilled and knowledgeable customers.
- Developers: Waterfall developers are to be plan-oriented, adequately skilled with the knowledge of external skills. While agile model needs developers that are knowledgeable, co-located and collaborative with amicable communicative and interactive talents. Agile approaches emphasize the cross-functional teams of developers, testers, subject matter experts and architects of application infrastructures.
A plan-driven waterfall model or an adaptive agile method are both advantageous and disadvantageous in several ways. If an enterprise has a large project at hand, the waterfall model is the best suited SDLC and if there is a small project at hand than the agile model is best suited. But. when it comes to medium-sized projects, both the models struggle in terms of handling and execution over medium-sized projects.
With rising costs and time constraints on development projects, the agile model can create apps more rapidly owing to its sprint tool which is a very short iterative method. While the waterfall model has large costing issues with staffing and tools required for several phases in the interactive relationships and with the focus on external testing, it incurs heavy costs on the project budget. So from the above, it is clear to choose the most suitable model according to your project requirements.