One of the first decisions developers face when beginning a project is, “What development method should we use?” It is a question that often results in heated debates and long discussions. A development methodology is simply a way of organizing all of the work that goes into a software development project.
The most popular methodologies are Waterfall and Agile developments. They both have their strength and weaknesses, as well as their share of die-hard supporters. But before deciding which is more appropriate for a specific assignment, it is essential to get a good understanding of both.
Waterfall takes the classic linear approach to software development. It follows a traditional methodology that usually includes a checklist of project stages. For example: gathering information, designing, coding a test unit, system testing, user acceptance testing, bug fixing, and final product delivery.
Each of the items in the checklist represents a distinct phase in the development process, which are generally completed in a systematic order – meaning that the project doesn’t advance to the next phase until the previous one is completed
Advantages of Waterfall Development
One of the pluses of Waterfall Development is that customers and developers can have a clear picture of what will be delivered very early in the project. This makes the whole interaction more straightforward, and expectations clearer. Additionally, the progress of the work can be more easily measured, as the full spectrum of objectives is known in advanced.
This method also makes it feasible for different members of a given team to be involved on other work, as different phases require different skill assets. For example, project managers can work with new clients on documenting what needs must be met, while developers can be working on established projects.
In waterfall development, design is completed early in the development cycle, so this makes it possible for several components to be designed for external system integrations. The software can also be designed more carefully, as there is a complete understanding of all deliverables. This can potentially reduce the risk of future errors.
Disadvantages of Waterfall Development
One area where waterfall development almost always falls short is in meeting requirements. Gathering customer requirements in an effective way is one of the most difficult parts of software development. Customers are often drawn away by too many details, and details are required early on in this methodology. A big problem is that customers are not always able to visualize their requirements from a mere document. Mock-ups and prototypes can often help, but it is hard for clients to put all of these elements together in order to get a clear picture of what the final product will look like.
Another risk of Waterfall development is that a customer may be dissatisfied with the final software. Because deliverables are dependent upon requirement documents, a customer may not be able to fully understand what will be delivered until the project is almost finished. By that time, it is usually very costly and time-consuming to make any changes.
The agile methodology is a team-based and interactive approach to development. Instead of creating a list of tasks that must be completed, the project is broken down into phases called “sprints.” A sprint defines a specific duration with a list of desired deliverables, which are planned one sprint in advanced. The deliverables inside a sprint are prioritized by business value as determined by the clients. If all of the work inside a sprint cannot be completed, then the work is re-prioritized for future sprints.
As the work in each sprint is completed, it is reviewed and evaluated by the client, which makes him or her the most important member in the agile methodology. As a result, Agile is often looked at as the method with the higher level of client engagement.
Advantages of Agile Development
With Agile, the client has many opportunities to be involved in the work being delivered, and to make changes and decisions throughout the entire project. The consumer benefits from a strong sense of ownership, and gets a chance to work closely with the development team.
Agile can also produce a basic version of working software more quickly. The development normally focuses more on the end-user, as there is higher involvement from the client. Late changes are easier and less costly to implement.
The use of time-boxed schedules makes it possible to predict costs, which can improve decision-making from clients.
Disadvantages of Agile Development
The increase in customer involvement can sometimes backfire, as there are customers who don’t have the time or interest to participate so closely in the project. Because Agile focuses on reprioritization and time-boxed delivery, it’s always possible that items will not be completed within the specified timeframes. Additional sprints are often needed, which can add to the overall cost of the project.
Additionally, the constant involvement of customer’s leads to additional requests and changes throughout the cycle
Because Agile projects require a lot of communication and a close working team, team members are usually required to be located in the same physical workplace. Remotely managing an agile team can sometimes bring up major issues.
The nature of Agile development might lead to a reduction in quality, as there is less focus on understanding the final product in the beginning. This becomes a more apparent issue on large-scale developments.
The classic waterfall method is steady and predictable, while the Agile method is quick, involved, and adaptable. Agile methods are great for reducing overheads. It benefits smaller teams that must meet constantly changing requirements. While Waterfall is more appropriate for larger unchanging projects.