What is Rapid Application Development?

Designing and building software is a dynamic and constantly-changing field. Because of this,  its models and methodologies must embrace its lively state and be sufficiently responsive to adapt with ease and effectiveness. In this article, we are going to answer the question what is Rapid Application Development (RAD), a model that is designed to develop software prototypes at a quick pace to validate functions and features.

To add a higher degree of detail and as defined by Techopedia, Rapid Application Development is a “suite of software development methodology techniques used to expedite software application development.” Rapid Application Development, which also sometimes goes by the name of Rapid Application Building (RAB) is an adaptive model for software development based on prototyping and iterative development, with no predefined planning involved. The rapid application development methodology is designed to put less emphasis on planning tasks and more emphasis on actual development and the rapid creation of a prototype.

The Rapid Application Development term was inspired by James Martin’s method called Rapid Iterative Production Prototyping (RIPP). Back in 1991, RIPP became the premise behind Rapid Application Development.

Now that we have a solid background, let’s dive into what is Rapid Prototyping specifically.

What is Rapid Prototyping?

What is Rapid Prototyping? Essentially, it is a collection of techniques used to build a prototype quickly. This rapid prototype solution is best suited for software projects that are driven by user interface requirements.  Oftentimes, graphical user interface builders are referred to as rapid application development tools. There are multiple rapid prototype development approaches which include adaptive, agile, spiral, and more. 

Rapid prototyping encompasses a graphical user interface (GUI) development environment, which allows users to drag and drop software elements to the application, for instance in web rapid application development. The driving force behind rapid application development is the belief that software can be developed faster and with a better end result by gathering requirements, building prototypes quickly, reusing software components, following a strict schedule, and adding flexibility to reviews and team communication.

Overall, RAD is a popular model that uses tools for software development such as requirement gathering tools, prototyping tools, computer-aided software engineering (CASE) tools, language development environments, testing tools, and more. 

In the simplest terms, the heart of Rapid Prototype Development is prototyping - the speedy creation of a scaled software application. Typically, rapid prototyping lacks full-scale functionality as it is focused on demonstrating the key functionalities of the application and further clarifying requirements, which helps end users envision the final solution version. 

Next, we are going to cover the key aspects of a rapid prototype in software development to better understand its importance and relevance in the industry.

Importance of a rapid prototype in software development

Rapid Application Development comes particularly handy in situations where quick delivery of a product is required. It is a well-suited model for projects that will require constant changes to prototypes throughout the process until the client is satisfied with the product.

RAD is as effective as the team of developers and software engineers who are enforcing the model and must be knowledgeable and committed to the project’s end goal.

The greatest value from leveraging a rapid prototype software development model is the “try before you buy” approach. This way, clients can take a look and play around with a functioning version of what is intended to be the final software solution to their request. 

Clients can use the prototype to explore functionalities, features, user experience, graphics, and more, and request changes as needed. This produces better feedback for the development team who is able to work on a live system to make necessary changes and reduce rejection levels by catering to specific client requests.

Long story short, the importance of using RAD lies in the fact that it allows clients and developers to fully understand software functionality from the earliest stages of development, which helps developers detect and correct issues early in the process. This leads to the reduction of rework and delivers a test-ready prototype that users can interact with. Additionally, RAD remains relevant in software development due to its strong emphasis on development over planning, to quickly develop software models. In a nutshell, due to prototyping and iteration, RAD allows users to effortlessly visualize the final version of a solution.

Defining requirements and goals for a prototype

Behind every software or piece of software, there is a reason for building it. This is where defining requirements and goals for a prototype come in for Rapid Application Development.

It is crucial for teams that are working on a rapid app development project to discuss and agree on the purpose of the desired software solution. To get to this point, a comprehensive review of the requirements and goals of the project must be researched to understand the project’s scope.

We will address the Rapid Application Development phases in the subsequent section to shed greater light on the overall method.

Rapid Application Development Phases

According to the foundation laid out by James Martin in his development of the RIPP method, there are at least four distinct Rapid Application Development phases:

• Requirements planning phase.
• User design phase.
• Construction phase.
• Cutover phase.

Next, we will detail each of these Rapid Application Development phases to fully comprehend what they are about and how they bring value to software development processes. The rapid application development process is almost the same as the software development process, but usually short and quick, allowing the swift testing of the application and the idea of future development.

Requirements planning phase

Similar to a project scoping phase, the requirements planning phase focuses on determining the goals and expectations of the project, as well as the underlying and potential issues that may arise and must be addressed during construction of the software solution. Because the essence of RAD is to provide deliverables quickly, it is fundamental to perform quick identification of functional requirements.

In Rapid Application Development, the requirements planning phase is significantly condensed in comparison to other project management methods, but it remains a critical step of the process. In it, developers, managers, clients, and other relevant team members involved in the project are in charge of researching, defining, and finalizing requirements. 

This phase combines elements of system planning and system analysis of the System Development Life Cycle (SDLC) to agree on business needs, scope, constraints, and requirements of the project. The phase is considered finalized once the team collectively agrees on key issues and obtains approval from each key stakeholder to avoid miscommunication and costly changes along the development road.

User design phase

In the user design phase, rapid application developers jump into work to build the user design through multiple prototype iterations. In Rapid Application Development, this is the most labor-intensive phase and what sets it apart from other project management methods. Basically, during the user design phase, users and developers work hand in hand to develop models and prototypes that include all system processes, inputs, and outputs.

During this interactive phase, users get to use and test each prototype of the product, at each stage, to ensure it is on the right path and that it meets or exceeds expectations. Users have the chance to provide continuous feedback so developers can quickly fix any bugs or defects in an iterative process.

In essence, the developer designs a prototype, the user tests it, and then both parties communicate with each other to see what worked and what didn’t. It is extremely helpful for developers to be in constant communication with the end user as they can tweak and improve the design until it is satisfactory for client standards.

Construction phase

The construction phase takes the approved prototype from the user design phase and converts it into a working model. In the Rapid Application Development model, users get to participate and suggest changes or improvements as the software is being developed. Since the vast majority of issues and changes were addressed during the iterative user design phase, developers can focus on the construction of the final working model more quickly than if they were following a more traditional project management strategy.

The construction phase is broken down into four smaller sub-tasks that include: preparation for rapid construction, program and application development (similar to the tasks in the SDLC), coding, and testing (unit, system, and integration).

Even though the client is heavily involved in the user design phase, they still have a chance to make any changes or modifications during the construction phase.

Cutover phase

The fourth and final phase: the cutover phase. In this phase, the finished product is ready to be launched into a live environment. It is similar to the implementation phase of the SDLC and includes data conversion, testing, and changeover to the new system, as well as user training.

It’s important to reiterate that all four phases are compact and compressed to help build, deliver, and deploy software much sooner than using a traditional method, which is what makes RAD such a successful software development alternative.

Now that the four phases of Rapid Application Development are explained, let’s explore the Rapid Application Development advantages and disadvantages.

Rapid Application Development Advantages and Disadvantages

As we mentioned previously, Rapid Application Development is a highly successful method that includes numerous benefits for software development teams and clients alike.  While it is recognized for its quick delivery and fast-paced prototyping, it also comes with a few disadvantages that must be considered before jumping into this method.

Here, we detail both Rapid Application Development advantages and disadvantages to get a clearer picture of this method.

Advantages

• With Rapid Application Development, the project can be broken down into smaller, more manageable tasks.
• RAD is flexible enough to allow frequent changes in requirements.
• Reviews are quick and the time between prototypes and iterations is short.
• With RAD, integrations can be applied from the earliest stages, which helps to quickly identify errors or complications within integrations. This prompts timely solutions.
• RAD has a task-oriented structure where team members can optimize efficiency by assigning tasks based on skills and experience.
• RAD places high importance on the reusability of components, which reduces both time and effort for projects.
• The product is delivered in a shorter time frame which allows users to work with it pretty quickly
• The user design phase demands constant communication between the development team and the user, which enhances efficiency and reduces the error rate during the design and construction phases.
• In a well-executed RAD method, the planning phase is short and there is a strong focus on highly iterative design and construction which leads to teams being able to accomplish more in less time without compromising client satisfaction.

Disadvantages

• Strong dependency on the technical strengths of team members to identify and determine business requirements. Thus, it requires highly skilled developers and designers on the team. 
• Since RAD is object-oriented, it can only be used with systems that can be modularized.
• RAD is not designed to work well with smaller projects as it requires heavy investment in automated code-generated tools and personnel who are skilled and specialized in the method.
• Features are relatively reduced to fit time constraints. Typically, features are pushed to later versions of the software to accommodate a shorter release period.
• Scalability is challenging when using RAD as the prototype evolves into a finished application.
• In RAD, there is little to no documentation, which makes it hard to track progress and issues of the software.

When RAD will work perfectly

As we mentioned before, RAD works perfectly for systems that can be modularized - broken down into separate units.

Specifically, there are a few scenarios where rapid development is a good fit:

• Systems can be modularized and distributed into a separate form.

• The rapid application development life cycle is available and teams understand each step included

• Modeling is emphasized and achieved via available and highly-skilled designers.
• Money is not a constraint in using automated code-generated tools.
• Clients expect a quick turnover of prototypes (typically within 2-3 months).
• Frequent changes are expected during the development process of the project.
• A rapid application development platform is carefully selected to satisfy the requirements of a prototype
• Rapid software development tools are available for free or the associated cost is acceptable for the prototyping project 

These scenarios are a sample of when RAD will work perfectly, but it is still up to the client and the judgment of available experts to determine if its the best approach to choose for a unique project for the rapid app.

Conclusion

RAD is a couple of decades old, but it remains relevant, active, and thriving in the current state of the IT industry which demands faster delivery of software to keep up with the market.  While there are several alternatives to RAD, such as Waterfall and Lean, it is still one of the top options for clients who like to work with highly-functioning prototypes, including rapid web application development and mobile app prototyping.

Clients and experienced developers must assess if RAD is the right path for a specific project. With this article, we hope to help you with this decision, selecting appropriate ​​rapid application development life cycle and rapid application development platform. and encourage you to Please reach out to us for more information about rapid application development real life examples. We are happy to help! 

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At Svitla Systems, we utilize numerous software development methodologies that are implemented by a strong, highly-skilled team of developers to help projects meet or exceed the expectations of committed clients.

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