What Is Rapid Application Development? 

Rapid application development is an agile software development approach that focuses more on ongoing software projects and user feedback and less on following a strict plan. As such, it emphasizes rapid prototyping over costly planning. Though often mistaken for a specific model, rapid application development (RAD) is the idea that we benefit by treating our software projects like clay, rather than steel, which is how traditional development practices treat them.

How did RAD programming come about? In the 1980s, Barry Boehm, James Martin and others recognized this obvious point: software was not a raw mineral resource. They saw software for what it was: infinitely malleable. Boehm and Martin took advantage of software’s inherent pliability when designing their development models: the Spiral Model and the James Martin RAD model, respectively. Since then, rapid app development has evolved to take on other forms and acted as a precursor to agile.

In this post, we take a deep dive into RAD, examining the methodology, reviewing its advantages and disadvantages, comparing it to agile, and exploring the tools.

RAD Methodology 

Though exact practices and tools vary between specific methods, the underlying rapid application development phases remain the same:

1. Define Requirements

Rather than making you spend months developing specifications with users, RAD begins by defining a loose set of requirements. We say loose because among the key principles of rapid application development is the permission to change requirements at any point in the cycle.

Basically, developers gather the product’s “gist.” The client provides their vision for the product and comes to an agreement with developers on the requirements that satisfy that vision.

2. Prototype

In this rapid application development phase, the developer’s goal is to build something that they can demonstrate to the client. This can be a prototype that satisfies all or only a portion of requirements (as in early stage prototyping).

This prototype may cut corners to reach a working state, and that’s acceptable. Most RAD programming approaches have a finalization stage where developers pay down technical debt accrued by early prototypes.

3. Absorb Feedback

With a recent prototype prepared, RAD developers present their work to the client or end-users. They collect feedback on everything from interface to functionality—it is here where product requirements might come under scrutiny.

Clients may change their minds or discover that something that seemed right on paper makes no sense in practice. Clients are only human, after all. With feedback in hand, developers return to some form of step 2: they continue to prototype. If feedback is strictly positive, and the client is satisfied with the prototype, developers can move to step 4.

4. Finalize Product

During this stage, developers may optimize or even re-engineer their implementation to improve stability, maintainability, and a third word ending in ‘-ility.’ They may also spend this phase connecting the back-end to production data, writing thorough documentation, and doing any other maintenance tasks required before handing the product over with confidence.

Both Boehm’s Spiral Model and James Martin’s RAD Model make use of these four steps to help development teams reduce risk and build excellent products. However, rapid app development has its drawbacks as well.

Rapid Application Development Advantages

We’ve covered some advantages of RAD already, but let’s restate them and expand.

Advantage Description
Speed In the traditional waterfall approach, developers were unlikely to go on vacation after delivering the product. Clients would invariably request changes ranging from interface to functionality after first delivery. With RAD, projects are more likely to finish on time and to the client’s satisfaction upon delivery.
Cost In rapid application development, developers build the exact systems the client requires, and nothing more. In waterfall, IT risks building and fleshing out complex feature sets that the client may choose to gut from the final product. The time spent building zombie features can never be recovered, and that means the budget spent on them is lost. RAD programming reduces this risk and therefore reduces the cost.
Developer Satisfaction In the traditional waterfall approach, developers work in silos devoid of feedback and positive affirmation for a product well-made. And when they finally get the opportunity to present their work to the client, the client may not roll out the red carpet for them. Regardless of how proud developers are of their work, if the client isn’t satisfied, developers don’t receive the accolades they so desperately seek. In rapid development environment, the client is there every step of the way and the developer has the opportunity to present their work frequently. This gives them the confidence that when the final product is delivered, their work receives appreciation.

 

Rapid Application Development Disadvantages

Those advantages sound pretty rosy, so let’s douse this warm positivity with a cold splash of reality.

Disadvantage Description
Scale A close-knit team of developers, designers, and product managers can easily incorporate RAD practices because they have direct access to one another. When a project expands beyond a single team or requires inter-team communication, the development cycle invariably slows and muddles the direction of the project. Simply put, it’s difficult to keep a large group of people on the same page when your story is constantly changing.
Commitment In waterfall, the client spent most of their time apart from the development team after completing specifications. This allowed clients to focus on their primary tasks and developers to focus on building. In rapid application environment, the frequent cycle of prototypes requires developers and clients to commit to frequent meetings that, on the outset, may appear to consume unnecessary cycles.
Interface-Focus Rapid application development methodology motivates developers to find the perfect solution for the client. The client judges the quality of the solution by what they can interact with—and often, all they interact with is a facade. As a consequence, some developers forego best practices on the back-end to accelerate development of the front-end-focused prototype. When it’s time to deliver a working product, they patch up the jerry-rigged server code to avoid a refactor.

 

Is Rapid Application Development Right For Your Team?

With the pros and cons of RAD programming laid out, let’s determine which types of projects benefit most from the rapid app development approach.

If you’re building an internal business tool or even a customer-facing portal, like an app or website, rapid app development techniques will help your team deliver a better experience to your end-user.

However, if your team is tasked with building mission-critical software (flight controls, implant firmware, etc.), the RAD methodology is not only inappropriate, but also irresponsible. A pilot with a failing control module or a heart attack survivor with a malfunctioning pacemaker cannot offer feedback on your prototype from beyond the grave.

So before you choose a rapid development environment for your project, ask yourself the following questions.

1. Is My Product Mission-Critical?

If end-users place their security or their very lives under your product’s control, it leaves your team with very little room for error, and a rapid development environment thrives only when we allow it to make and correct errors.

However, exceptions exist for products we are able to simulate without placing anyone in harm’s way. But if your project must be 100% flawless before you expose it to the end-user, rapid app development is not the choice for you.

2. Do I Have Access To End-User and Client Feedback?

As mentioned throughout this post, rapid app development requires buy-in from the end-user; they must be willing and able to provide feedback as well as subject themselves to user-testing.

As for clients, they must commit to providing frequent feedback during the iterative, on-going rapid application development process.

3. Can I Divide My Deliverable?

In a rapid development environment, your team exposes the end-user to prototypes early and often, frequently with incomplete or missing user flows. Therefore, you must divide your project such that your team may build and present the product in portions (or modules), rather than in one complete whole. Often, a barrier to modularization occurs on the backend where your project must integrate with multiple third parties before delivering a business use-case to the end-user.

You can get around this requirement by relying on data synthesis, a process which generates fake data to resemble in approximation the data set your end-users expect. This enables you to model behaviors with your prototype without going the extra mile to build connectors in advance of needing them.

4. Can My Team Iterate Quickly?

The final, and most obvious question to ask yourself, is whether your team can iterate at a RAD programming pace. Certainly, traditional software techniques generate code more malleable than steel, yet we often build products with bones at their core — breakable, but not without excruciating pain. Boilerplate code, the bare minimum code which forms the skeleton of our project, consumes a non-zero percentage of our effort, and often a lot greater than zero.

Building out the core of your application and righting the wrong assumptions made along the way sap time and energy from delivering working prototypes. And beyond development, you need a design and product team willing and able to rapidly context-switch between ideation and assimilation (processing feedback from clients and end-users).

This practice is not imbued in all teams, but all teams can learn it and several tools can help. If your team cannot iterate quickly or you cannot afford the tools which enable them to do so, RAD development may not be a suitable choice for your work.

Let’s take a look at an example of a team that applied RAD development methodology to their work, and won — big time.

Rapid Application Development Case Study: Keypoint Intelligence and Canon

Keypoint Intelligence offered a wide array of services to clients ranging from market intelligence to product research to custom software development. Keypoint won much of its business by submitting prototypes in response to RFPs. Unfortunately, varying requirements forced Keypoint to start from scratch with nearly each project and build out new boilerplate code before delivering their prototypes. As a consequence, their sales cycles ran months-long and projects spent over a year in development before going into production.

To gain an advantage over their competitors, Keypoint Intelligence turned to OutSystems. OutSystems is a AI-enhanced application platform that facilitates rapid application development by integrating back and front-end programming and deployment in a unified visual interface. By employing a modern development platform, Keypoint Intelligence began to deliver working prototypes weeks ahead of the competition, beating their own benchmarks, and increasing their development pace by 6x.

Long-time partner Canon then tasked Keypoint with building a cross-platform mobile front-end engagement solution complete with a backend content management system. A traditional team of 10 may have delivered the product in between 6-months and a year, but two developers equipped with our RAD tools delivered both mobile apps in just under three months.

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RAD vs. Agile

Those who research development methodology compare one framework to another. Most commonly, rapid application development is directly contrasted with agile software development. Unfortunately, this comparison is challenging to draw. RAD is a forbear of agile, but agile encompasses far more than a development model. It is more of a philosophy than a methodology.

In an attempt to show this, we have contrasted the core principles of each concept:

Table showing the differences between agile and rapid application development

Rapid Application Development Tools

As you may now understand, rapid application development is more of a software development methodology rather than a specific language, tool, or interface. However, tools can help facilitate rapid prototyping, development, and feedback solicitation.

Design and Prototyping Tools

The products in this category help teams craft interactive designs at impressive speeds. And some tools on this list, like Webflow, allow designers to export the completed design as a functional cross-browser prototype.

Tool Prototype Runs On
Adobe Experience Design Web, Mobile  macOS, Windows
Balsamiq Web, Mobile macOS, Windows
InVision Web, Mobile, Wearable macOS
JustInMind
Web, Mobile, Wearable macOS, Windows 
Mockplus Web, Mobile macOS, Windows
Origami Studio  
Mobile macOS
Proto.io
Web, Mobile, Wearable Web
Sketch Web, Mobile macOS
Webflow Web, Mobile  Web

User Testing and Feedback Tools

As noted many times thus far, RAD methodology requires frequent feedback from clients and end-users. And in modern workflows, developers who work offsite prefer to solicit feedback remotely rather than book travel and accommodations each and every time they require input from clients.

Tool Platforms Best For
Conjure
Web Clients
InVision
Web, Mobile Clients
Red Pen Web. Mobile  Clients
Usability Sciences Web, Mobile End-Users
Userbrain
Web End-Users
UserTesting Web, Mobile End-Users
Validately
Web, Desktop, Mobile End-Users

Rapid Application Development Tools

If your team has strict technology requirements or a limited skill set, it’s simpler to stick with what they know. Often you cannot justify the cost of migrating technologies. But if you’re willing to consider a new approach to development, the tools in this category will accelerate your production cycle. 

Tool Builds
Alpha Software
Windows, Web, Mobile
AppGyver
Mobile 
Appian 
Web, Mobile
Kony
Web, Mobile
Zoho Creator Web
Mendix
Web, Mobile
OutSystems 
Web, Mobile
Salesforce AppCloud Web, Mobile
Spring
Mobile
Visual LANSA
Windows, Web, Mobile
WaveMaker
Web, Mobile

 

How OutSystems Enables Rapid Application Development

We are a modern AI-enhanced application platform. And that means our product goes beyond enabling a rapid application environment by including hosting, dynamic scaling, release automation, performance monitoring, user management, version control, and much more. But at the core of our offering lies a powerful development environment. Our platform combines high-productivity tools that automate and simplify complexity, with the power and expressiveness of traditional development, thus enabling IT-adjacent roles to veteran IT professionals to build enterprise-grade web and mobile applications fast.

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