How do the top software development methodologies (waterfall, rapid application, agile, and DevOps) work? And which method is best for your project?
Successful projects are managed well. To manage a project efficiently, the manager or development team must choose the software development methodology that will work best for the project at hand. All methodologies have different strengths and weaknesses and exist for different reasons. Here’s an overview of the most commonly used software development methodologies and why different methodologies exist.
1. Agile Development methodology
Teams use the agile development methodology to minimize risk (such as bugs, cost overruns, and changing requirements) when adding new functionality. In all agile methods, teams develop the software in iterations that contain mini-increments of the new functionality. The Agile methodology was developed as a response to growing frustrations with Waterfall and other highly structured, inflexible methodologies. This approach is designed to accommodate change and the need to produce software faster. Agile values individuals and their relationships and interactions over tools; it features customer collaboration throughout the development process; it responds to change instead of following a set-in-stone plan; and it focuses on presenting working software, rather than documentation.
Unlike Waterfall, Agile is well equipped to handle the complexity and variability involved in development projects.Using the Agile approach, teams develop in short sprints or iterations, each of which includes a defined duration and list of deliverables, but in no particular order. During sprints, teams work towards the goal of delivering working software (or some other tangible, testable output). Agile is collaboration-heavy, focusing on team strengths and efficiency, along with internal feedback from various departments and clients. Client satisfaction is the highest priority with the Agile approach, which teams achieve by continuously delivering working, tested, prioritized features. Below is the figure representing agile methodology
Pros: The primary benefit of agile software development is that it allows software to be released in iterations. Iterative releases improve efficiency by allowing teams to find and fix defects and align expectation early on. They also allow users to realize software benefits earlier, with frequent incremental improvements.
Cons: Agile development methods rely on real-time communication, so new users often lack the documentation they need to get up to speed. They require a huge time commitment from users and are labor intensive because developers must fully complete each feature within each iteration for user approval.
Agile development methods are similar to rapid application development (see below) and can be inefficient in large organizations. Programmers, managers, and organizations accustomed to the waterfall method (see below) may have difficulty adjusting to an agile SDLC. So a hybrid approach often works well for them.
There are many different forms of the agile development method, including scrum, crystal, extreme programming (XP), and feature-driven development (FDD), detailed below:
1.1 Scrum
Another way to implement the Agile approach, Scrum borrows from Agile’s foundational beliefs and philosophy that teams and developers should collaborate heavily and daily. With Scrum, software is developed using an iterative approach in which the team is front and center experienced and disciplined workers on smaller teams might find the most success with this method, as it requires self-organization and self-management.
Team members break down end goals into smaller goals at the beginning and work through them using fixed-length iterations or sprints to build software and showcase it often (which usually last two weeks). Meetings play an important role in the Scrum approach, and during each sprint, daily planning meetings and demos take place to follow progress and gather feedback. This incremental method promotes quick changes and development and adds value to complex projects. Scrum incorporates the structure and discipline of more traditional software development methodologies with the flexibility and iterative practices of modern Agile.
1.2 Extreme Programming (XP)
Another Agile framework, Extreme Programming (or XP) focuses on producing higher quality software using the best practices in software development. As with most Agile approaches, XP allows for frequent releases in short development sprints that encourage change when needed. In general, XP follows a set of values, rather than steps, including simplicity (develop what is required, nothing more); communication (teams must collaborate and work together on every piece of the software); consistent feedback; and respect. Extreme Programing requires developers to first plan and understand the customer’s user stories their informal descriptions of certain features. Other practices include: scheduling and dividing work into iterations. Design with simplicity in mind, code and test often, which helps to create fault-free software. Listen to feedback to best understand the functionality, and then test more.
1.3 Feature-Driven Development
An iterative and incremental approach to software development, Feature-Driven Development (FDD) is derived from the Agile methodology and is considered one way to implement it. Similar to Waterfall, FDD is typically viewed as an older methodology, a sort of precursor to modern Lean/Agile implementations. FDD still focuses on the goal of delivering working software frequently and is an especially client-centric approach, making it a good fit for smaller development teams. Features are a foundational piece of FDD. Features are client-valued pieces of work that, according to the FDD approach, should be delivered every two weeks.
To produce tangible software often and efficiently, FDD has five steps, the first of which is to develop an overall model. Next, build a feature list and then plan by each feature. The final two steps—design by feature and build by feature—will take up the majority of the effort. At each step, status reporting is encouraged and helps to track progress, results, and possible errors. Although efficient response to change is one of FDD’s better attributes, an understanding of the client’s requirements and the overall model at the beginning of the project can reduce any surprises during development. Additionally, any feature that takes longer than two weeks to design and build must be further broken down into separate features until it meets the two-week rule. The rigid structure of FDD make it less desirable to teams who balance project-driven and break-fix types of work.
2. DevOps Deployment methodology
DevOps is not just a development methodology but also a set of practices that supports an organizational culture. DevOps deployment centers on organizational change that enhances collaboration between the departments responsible for different segments of the development life cycle, such as development, quality assurance, and operations.
Pros DevOps is focused on improving time to market, lowering the failure rate of new releases, shortening the lead time between fixes, and minimizing disruption while maximizing reliability. To achieve this, DevOps organizations aim to automate continuous deployment to ensure everything happens smoothly and reliably. Companies that use DevOps methods benefit by significantly reducing time to market and improving customer satisfaction, product quality, and employee productivity and efficiency.
Cons: Even in light of its benefits, there are a few drawbacks to DevOps:
- Some customers don’t want continuous updates to their systems.
- Some industries have regulations that require extensive testing before a project can move to the operations phase.
- If different departments use different environments, undetected issues can slip into production.
- Some quality attributes require human interaction, which slows down the delivery pipeline.
3. Waterfall Development method
Many consider the waterfall method to be the most traditional software development method. The waterfall method is a rigid linear model that consists of sequential phases (requirements, design, implementation, verification, maintenance) focusing on distinct goals. Each phase must be 100% complete before the next phase can start. There’s usually no process for going back to modify the project or direction. When it comes to software development, Waterfall is the most traditional and sequential choice. Although it’s usually viewed as an ”old school” or outdated method, it’s helpful to understand the history and structure of Waterfall to better appreciate the flexibility of more modern methodologies. First created in 1970, Waterfall was one of the most prominent methodologies for several decades because of its plan-driven approach.
Waterfall requires plenty of structure and documentation up front. It is divided into self-contained stages or steps. The first stage is vital, requiring a full understanding by both developers and customers of the project’s demands and scope before anything begins. The stages are relatively rigid and often follow this sequence: determine the project’s requirements and scope, analyze those requirements, design, implement, test, deploy and finally, maintain. There’s a lack of flexibility with this approach, meaning what is decided by the customer and developer at the beginning must be seen through. Should any changes need to be made or mistakes addressed toward the end stages, the Waterfall method generally requires a full restart.
Typically, one stage must be finished before the next can begin, which can help with organization and assignments. And because the full scope of the project is understood in advance, software progress can easily be measured. Waterfall is often utilized by large, plan-driven teams who have a very clear understanding of the project’s scope;—however, development teams who don’t operate in a vacuum will likely find better results with the flexibility and agility of more modern methodologies.
Pros: The linear nature of the waterfall development method makes it easy to understand and manage. Projects with clear objectives and stable requirements can best use the waterfall method. Less experienced project managers and project teams, as well as teams whose composition changes frequently, may benefit the most from using the waterfall development methodology.
Cons: The waterfall development method is often slow and costly due to its rigid structure and tight controls. These drawbacks can lead waterfall method users to explore other software development methodologies.
4. Rapid Application development
Rapid application development (RAD) is a condensed development process that produces a high-quality system with low investment costs. Scott Stiner, CEO and president of UM Technologies, said in Forbes, “This RAD process allows our developers to quickly adjust to shifting requirements in a fast-paced and constantly changing market.” The ability to quickly adjust is what allows such a low investment cost. The rapid application development method contains four phases: requirements planning, user design, construction, and cutover. The user design and construction phases repeat until the user confirms that the product meets all requirements.
Pros: Rapid application development is most effective for projects with a well-defined business objective and a clearly defined user group, but which are not computationally complex. RAD is especially useful for small to medium projects that are time sensitive.
Cons: Rapid application development requires a stable team composition with highly skilled developers and users who are deeply knowledgeable about the application area. Deep knowledge is essential in a condensed development timeline that requires approval after each construction phase. Organizations that don’t meet these requirements are unlikely to benefit from RAD.
Which Software Development Methodology Should I Use?
These four software development methodologies are the most pervasive in software development. Each one has its own strengths and weaknesses and works effectively in different situations.
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