What is RAD?RAD refers to a development life cycle designed to give much faster development and higher quality systems than the traditionalSystems Development Lifecycle (SDLC). It is designed to take advantage of powerful development software like CASE tools, prototyping tools and code generators. The key objectives of RAD are: High Speed, High Quality and Low Cost. RAD is a people-centred and incremental development approach. Active user involvement, as well as collaboration and co-operation between all stakeholders, is imperative. Testing is integrated throughout the development life cycle so that the system is tested and reviewed by both developers and users incrementally. A typical RAD life cycle is composed of the following stages.

Note: If the requirements are obvious, the first two Stages may be combined.The RAD lifecycle is similar to the traditional Systems Development Lifecycle in some ways. It involves some of the same steps. However, it is really a compressed version of the traditional approach, designed to be executed over a very short period of time (for example 3 months).RAD in SDLCMapping between System Development Life Cycle (SDLC) of ITSD and RAD stages is depicted as follows:

Note: If a combined Feasibility Study (FS)/Systems Analysis & Design (SA&D) is to be conducted, the Requirements Planning (RP) and User Design (UD) stages will be conducted consecutively. If a SA&D is to be conducted without a previously conducted FS, the activities in the Requirements Planning (RP) stage still have to be done when necessary, before starting UD stage.Essential ingredients of RADRAD has four essential ingredients: Tools Methodology People ManagementIf any one of these ingredients is inadequate, development will not be high speed.

ToolsThe use of powerfulCASE toolswill provide automation support for systems development through features such as code generation and automatic consistency checking. CASE tools that generate prototypes can be used to support an iterative development approach such as RAD, allowing end users to see the application evolve as it is being built.

Case toolsMethodologyThe most effective family of techniques must be formalised and used to deliver the system. A complete list of tasks is provided to ensure that no essential activity is overlooked, while techniques are fully documented to ensure that a task is performed in the proper way.PeopleThe best people must be well-trained in both the methodology and the tools. Small teams that work consistently well together should be grouped together on assignments.ManagementThe project must be managed for speed through the use of techniques such as facilitatedJoint Requirements Planning (JRP)andJoint Application Design (JAD)workshops to extract users' requirements quickly. Timebox Management is used in Rapid Construction to iteratively deliver the system to the users.

JRP

JADBenefits of RADThe following benefits can be realised in using RAD: High quality systems will be delivered because of methodology, tools and user involvement Business benefits can be realised earlier Capacity will be utilised to meet a specific and urgent business need Standards and consistency can be enforced through the use of CASE tools Build what users need Correct the software and/or misconceptions as they arise Shift the design to accommodate new needs and other changes Resolve bugs early onIn the long run, we will also achieve: A reduction in the time required to get systems developed Increased productivity of developersRAD structural model overviewStructure ComponentThe structure of RAD is divided into Stages. Each Stage consists of a number of tasks. The following diagram is a structural model of how RAD tasks are organised:

For each Task, the Structural Model defines clearly the objectives, inputs, outputs, techniques to be used, roles involved and a list of sub-tasks to be carried out.Overview of structureThe following diagram shows the Stages and Tasks in RAD:

[click on image for a larger view]Abstracted from : An Introduction to Rapid Application Development (RAD) The Government of the Hong Kong Special Administrative Region Ref. No.: G47a Feb 2002 5-1 Version 1.1When should you use RAD? When the system being developed is data entry and data display intensive. RAD is not suitable for computationally intensive programs When specifications are loosely defined - because RAD includes methods for quickly capturing user requirements through JRP and JAD sessions. When the application program is unique to a business - ie not available off the shelfWhat to expect in this resource packTheory about RADThis resource provides an overview of RAD concepts and how you can apply the theory to a real solution.Example of RADThis resource provides a simple example of RAD development using several different tools.Possible CASE tools or RAD toolsThis resource provides links to tools that can be used for Rapid Application Development. The resource does not recommend the use of specific tools.What you should not expect from this resourceGuidance in using specific toolsThis resource provides links to several tools; some of the links include tutorials, however this resource does not provide guidance on using tools to develop solutions.Guidance in implementing specific methodologies and techniquesOnly one technique is exampled in this resource, however there are many other techniques and tools available in the market. The specific technique required to develop a solution will be based on the type of solution required and the tools used to develop the solution.