#rad model

Test-driven development projects require mobility and flexibility. Hence rapid development model suits the best. It is perfect for developing consumer-facing mobile apps where the ultimate focus is the user experience.  

Here is how the RAD model works in 5 key stages:  

The first stage is always about defining and particularizing schedules, goals, and objectives and setting the budget for the software.  

Then starts, the process of prototyping. For that requires the collaboration of designers and developers to work with the clients to optimize the prototyping process.  

The third step involves collecting feedback. As the developers start developing the software using the RAD model, clients start putting in their feedback to make the output worthy.

Then the developers need to test the code they have written to create the software. This is one of the most important steps in the RAD model that involves checking and rechecking if the software is running properly and reaching the client’s expectations or not.  

The last and final stage of the rapid application development model is finalizing. Here the developers implement the last changes and launch the software. Starting from data conversion and system switchover to last-minute adjustments, this stage includes all.  

What is Rapid Application Development?

Rapid Application Development model is a type of Agile software development and came into existence when it came to know that traditional waterfall model is not effective when the software is in testing phase. When the program is in testing phase, then changing the core functionalities is too hard.

Rapid Application development model mainly focuses on the rapid prototyping rather than complete require gathering at the same time. Speedy feedback over lengthy development and testing cycles can be taken in RAD model. Due to this, changes needed to take place at the time of final testing will reduce and so reduces the complexity to do changes at the extreme end of development phase.

When you can use Rapid Application Development ?1. When you need to complete a project quickly-

Rapid Application Development is your best choice among other development models when you have got a tight deadline to meet or you’re under pressure to deliver something that works properly. Decision for using RAD saves your time that you would otherwise need to go through a long requirement planning and design phase. With RAD, you can take an on-the-fly approach, which can change the direction of the development efforts, on a dime.

2. When You Can Reliably Test Your Prototypes?-

If you have a lot of users and they can give you accurate feedback, then RAD is your best choice. Prototypes built through the Rapid Application Development Model depends on the feedback from previous iterations, so accurate feedback from dependable sources is progressively helpful.

3.When You’ve Got the Budget-

The Rapid Application Development method is cheaper than other development models. However, there are some cases where RAD can be expensive. At that time you may need to hire technology experts and give them fitting salaries but on the brighter side, if you’ve got the staff then you can get your idea developed much quicker than any other model.

4. Minimum Changes and Less Time –

Rapid Application Development, commonly known as RAD, is a software development life cycle that is designed to give faster development times and higher quality results than the traditional software development life cycle. It focuses on gathering customer requirements through workshops/focus groups, early testing of the prototypes by the customer using iterative concept, reusing existing components, continuous integration and rapid delivery.

The software development model describes the various phases of the process and the sequence in which they will occur. The success of any software project depends in large on the methodology or process that the project follows. There are several Software models that projects may choose to follow. This model is decided based on the type or complexity of the product architecture.

The seven software development models are as follows:

The Waterfall Model

The V model

The Incremental model

The RAD model

The Agile model

The Iterative model and

The Spiral model

Let us understand the stages and the sequence of process flow for each of the above mentioned models.

The Waterfall Model: One of the earliest models used is the waterfall method. It was also one of the most prominently used models. In this model, all the stages of development follow one after the other. They do not extend into one another; each has to complete fully for the next to start. The stages in the waterfall method are:

Requirements gathering phase

Design phase

Developmental phase

Testing phase

Deployment or Release phase

And the maintenance phase.

The Waterfall model is chosen when:

The project is very simple and well understood.

You have worked on similar projects and have the expertise in handling them.

The scope of work is not expected to change.

Resources are not shared amongst other projects, that is, you have dedicated resources with the required expertise.

Pros and Cons of Using the Waterfall model: Pros:

Very simple to use

Does not require hiring a PMO to manage the project.

Works well on small and fixed scope projects.

Cons:

Does not help in cutting short, long projects.

Cannot be used for projects with unfixed or variable scope.

An un-thought of change done in a later stage of development proves to be very expensive.

A working version of the project cannot be seen till the testing stage is reached.

The V Model: The V Model is similar to the waterfall method, In this model too, each of the phases occur sequentially; one after the other. One phase has to complete before the next can start. This model is also called as the Validation and verification phase. The model is in the shape of a V, with one arm of the V having all the Validation phases and the other having all the Verification phases. Both these arms are connected with the “coding” phase. The various phases of the V Model are:

Requirements phase: The SRS is created as a part of the validation arm, and the corresponding Systems test plan is created in the verification arm.

Design phase: The HLD and LLD design docs are created in this phase on the validation arm, in parallel the Integration test plan is created on the other arm of verification.

Implementation phase: Coding is done in this phase, once coding is completed the project moves on the other side of the V and now the test plans created earlier are put to use.

Coding phase: Developers understand the design documents and start coding in this phase.

This model is successful when the projects are relatively simple and technical expertise is available.

Pros and cons of the V model: Pros:

Simple to use

Chances of finding a change request come earlier in the life cycle, hence reducing costs.

Defects in design are also caught early.

Cons:

Should be used only for well understood and simple projects

Product prototypes can be created or presented only later in the life cycle.

The Incremental Model: In the incremental model, the product is built gradually. The product is split into modules and each module is developed one by one. Each module goes through the waterfall model; each having its own design, development and testing phases. This model has multiple Waterfall methods.This model is used when:

The technology to be used is relatively new.

Technical expertise is not easily available.

The product has to be introduced in the market quickly.

The requirements are complex and changes in them are foreseen

Pros and Cons of the Incremental Model: Pros:

Product prototype can be built and released early.

Scope and requirements can be altered with lesser overheads.

Technical expertise can be created while the project is in progress.

Cons:

Costlier than the waterfall method.

Architects have to be strong to understand the bigger picture and then break it into smaller modules.

Clicks here to read Part 2 of this article which describes the remaining software development models in detail.