RAD and ARAD

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RAD and ARAD

• Barbara Tacchino

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Summary

• RAD (Rapid Application Development)
• Definition and features
• Development cycle
• Team, tools, documentation, problems
• ARAD (Architected Rapid Application Development)
• Definition and features
• The IBM ARAD solution IBM Rational Rapid
  Developer
• A business application scenario

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What is RAD?

• Is a software development process model that has
  been developed to respond to the need to deliver
  systems very fast
• Actually it allows usable systems to be built in
  as little as 3-6 months
• It has been developed in the early 1990s
• It takes inspiration from spiral model
• Its goals are faster, better, cheaper

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Spiral model (Barry Boehm, 1988)

• Planning determination of goals and alternatives
• Risk analysis analysis of alternatives and
  identification/resolution of risks
• Engineering development of the product of the
  next level
• Customer evaluation evaluation of results of
  engineering from the point of view of the
  customer

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Problems addressed by RAD

• With conventional methods, there is a long delay
  before the customer gets to see any results
• With conventional methods, there is nothing until
  100 of the process is finished, then 100 of the
  software is delivered
• With conventional methods, software development
  can take so long that the customers business has
  fundamentally changed by the time the system is
  ready for use
• Satisfying the customer at the time of delivery

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When use RAD?

• Project scope focused, where the business
  objectives are well defined and narrow
• Project data already exist
• Project decisions can be made by a small number
  of people who are available and co-located
• Project team very small (six people)
• Project technical architecture defined and clear
  and the key technology components are well known
• Project technical requirements are reasonable
  and well within the capability of the technology
  being used
• Intensive involvement of the end user in the
  design of the system (JAD, Joint Application
  Development)

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Features of RAD

• Use of prototyping, which helps users visualize
  and make adjustments to the system
• Use of a CASE repository to facilitate the re-use
  of templates, components and systems
• Use of an integrated CASE toolset to generate
  bug-free code from a fully validated design
• Development of a task structure that encourages
  parallel project activities

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JAD

• Is a management process which helps developers
  teams work effectively with users to develop
  information technology solutions
• Purpose define the project, design the solution
  and monitor the project until it reaches
  completion

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Prototyping

• In general creation of a small-scale prototype
  of the system used to test out certain key
  features
• less functions
• less efficient
• With RAD the prototype becomes a part of the
  delivered system

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RAD development cycle
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RAD uses iterative prototyping

• JRP (Joint Requirement Planning) meeting
  high-level end-users and developers meet in a
  session to generate a list of initial
  requirements
• Iteration
• Designers review the prototype
• Developers build/evolve the prototype based on
  current requirements
• Customers try out the prototype and evolve their
  requirements
• Focus Group Meeting (JAD) customers and
  developers meet to review product together and
  refine requirements
• Requirements and change requests are timeboxed

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Stages of RAD Requirements Planning

• takes one to four weeks to complete
• is defined during a JRP meeting
• consists of a review of the areas immediately
  associated with the proposed system
• produces a broad definition of the system
  requirements in terms of the functions the system
  will support
• deliverables from this stage include
• an outline system area model (entity and process
  model)
• a definition of the systems scope
• a cost justification for the new system

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Stages of RAD User Design

• is defined during JAD meetings
• consists of a detailed analysis of the business
  activities related to the proposed system to
  outline the design
• The team defines entity types and creates action
  diagrams defining the interactions between
  processes and data
• System procedures are designed and preliminary
  layouts of screens are developed
• Prototypes of critical procedures are built
• A plan for implementing the system is prepared
• Together with the next stage, User Design
  consists of a series of iterations

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Stages of RAD Construction

• Developers, working directly with users, finalize
  the design, build and test the prototype
• The deliverables include documentation and
  instructions necessary to operate the new
  application and procedures needed to put the
  system into operation
• Timebox and parallel development involves
  monitoring progresses to complete each task
  quickly
• The prototype is reviewed by users
• Requirements document can be modified, so another
  iteration starts

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Stages of RAD Transition

• the period during which the newly developed
  system gradually replaces existing systems
• User acceptance end of iterations
• Developers train users to operate the new
  application
• objectives
• Install the system in production operation with
  minimal disruption of normal business activity
• Maximize the effectiveness of the system in
  supporting the intended business activities
• Identify potential future enhancements

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RAD team

• should include both developers and users of the
  system and each person can play several roles
• User Coordinator appointed by the Sponsor to
  oversee the project from the user perspective
• Requirements Planning Team high-level users
  participating in the requirements planning
• User Design Team participates in the design
  meetings
• User Review Board review the system after the
  construction and decide if modifications are
  needed
• Training Manager responsible for training users
  to work with the new system
• Project Manager oversees the development effort
• Construction (SWAT) Team two to six developers
  highly trained to work together at high speed.
  SWAT stands for Skilled Workers with Advanced
  Tools. This team builds the system and also
  participate in the design meetings
• Meeting Leader organizes and conducts the
  meetings

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RAD tools

• RAD depends entirely on automated tools
• CASE software provides planning, analysis and
  design workbenches that are fully integrated so
  that one tool directly employs the information
  from another
• repository stores the knowledge from the multiple
  tools in an integrated manner
• code generator is fully integrated with the
  design toolset and allows the developer to
  design, modify, generate code and test as quickly
  as possible

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RAD documentation

• Customers, developers and management must accept
  informal deliverables
• Notes from user meetings rather than formal
  requirements documents
• Notes from designers meetings rather than formal
  design documents
• Principle create the minimum documentation
  necessary to facilitate future development and
  maintenance

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Problems of RAD

• criticized because it lacks a methodology and a
  designed architecture
• flexibility of RAD systems decreases as
  applications grow
• RAD tends to fail when
• Application must interoperate with existing
  programs
• Performance and reliability are critical
• The system cannot be modularized
• New technologies are used

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Introduction to ARAD

• IBM acquired Rational Software
• Starting point RUP (Rational Unified Process)
• It is a software development process model which
  includes a lot of features of the spiral model
  (iteration, prototyping, phased development)
• Each phase is supported by visual tools
• It establishes four phases of development, each
  consisting of one ore more executable iterations

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Phases of RUP
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What is Architected RAD?

• an evolution of RAD which supports the creation
  of enterprise applications and has a formal
  process
• a version of the Rational Unified Process (RUP)
  that has been optimized for RAD
• the team is made up of eleven people a project
  leader, one analyst, eight developers and one
  technology architect
• is characterized by
• a unified process
• business modeling with UML
• rapid application development

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Unified ARAD process

• One problem of RAD is that it lacks a formal
  process
• Unified ARAD process unifies the team by
  providing roadmaps for application development
  that include defining flows, stakeholders and
  explaining how they interrelate

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Business modeling with UML

• RAD lacks a focus on the business processes that
  drive software requirements
• ARAD focuses on business modeling
• analysts can use UML to analyze business
  requirements, define business use cases, define
  the information model for the application and the
  business processes and business rules

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Business modeling

• Specify the knowledge about the domain of the
  problem using UML techniques before analyzing
  requirements

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The IBM ARAD solution IBM Rational Rapid
Developer

• is the new Rational software solution for ARAD
  (2003)
• provides an integrated application development
  environment and process that unifies team skills
• supports rapid application development,
  integration and architected code construction
• helps team rapidly deliver n-tier business
  applications without encountering the complexity
  of the underlying technology platforms
• enables late binding of construction patterns and
  deployment platforms
• integrates with the IBM Rational lifecycle
  toolset
• covers the complete lifecycle, from requirements
  to deployment
• supports parallel development, version management
  and change management

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Patterns

• are a recent software engineering problem-solving
  discipline that emerged from the object-oriented
  community

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IBM Rational Rapid Developer workflow

• Rational Rapid Developer follows a model-driven
  approach to application development
• Nine out of ten members of the development team
  are focused on business process
• Development team begins by capturing requirements
  and assessing existing assets (or requiring new
  ones) to support the process

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Model Driven Approach (MDA)

• A way of writing specification based on a
  platform-independent model
• a MDA specification consists of a
  platform-independent base UML model, plus one or
  more platform-specific models and interface
  definition sets, each describing how the base
  model is implemented on a different middleware
  platform

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IBM Rational Rapid Developer workflow (2)

• The next step focuses on visual modeling the
  application and designing Web, wireless, XML,
  messaging and Web services transactions
• Rational Rapid Developer provides essential UML
  models

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IBM Rational Rapid Developer workflow (3)

• The application, completely visually modeled,
  resides in the application repository before it
  is cast into a chosen technology platform

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IBM Rational Rapid Developer workflow (4)

• Now the technology expert decides how the
  application will be constructed and deployed
  choosing the platform and determining patterns

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IBM Rational Rapid Developer workflow (5)

• Based on choices by the team's technical expert,
  Rational Rapid Developer automatically constructs
  the final application in a matter of minutes, and
  even automatically compiles, test and deploys it
• Each stage can be iterated
• Users involvement

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A business application scenario

• Lets use the ARAD process to design this
  marketplace application

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Business requirements with UML

• Use cases that describe the Web, wireless and
  integration functions of the application
• IBM Rational Rapid Developer provides a project
  estimator that can estimate the work effort
  required to develop the application, based on
  these use cases
• Model visually the application use some of the
  UML models such as UML Class Model

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Class Model
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Business requirements with UML (2)

• Import legacy database models the database
  schema is automatically converted into an XML
  file and imported into Rational Rapid Developer
  as a class model
• Rational Rapid Developer can perform
  object-to-relational mapping and create database
  schema for relational databases
• Define business rules using a Java business rule
  editor. Rule examples are inventory check, order
  pricing, customer credit check
• Define business processes as state chart/activity
  diagrams
• They are purely analytical and do not lead to any
  direct code construction

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Develop user interfaces rapidly

• Define site flow models for each actor of the
  application these models reflect the user
  interface use cases
• Define the look and feel of the application with
  styles and themes
• Design Web pages it is visual and rapid and
  facilitated by the Page Architect feature

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Layout pages visually
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Develop user interfaces rapidly (2)

• Design page logic it is written in Java using
  the Logic Architect
• IBM Rational Rapid Developer provides nearly 100
  code templates, so developers need only fill in
  parameters to write code
• IBM Rational Rapid Developer automatically
  construct, compiles and deploys the application
• Internationalization of pages a translation file
  is created and imported

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Business Logic
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Rapid integration development

• Enterprise integration with XML
• Integration with Web Services IBM Rational Rapid
  Developer discovers the services published in a
  public repository, than the developer clicks on a
  service and a service call is inserted in the
  code like a Java method call
• The developer specifies only the method call
  parameters
• IBM Rational Rapid Developer will automatically
  handle all the mechanics of invoking the service,
  using SOAP request/ response mechanism

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Integration with Web Services
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N-tier architected deployment

• The technology architect can deploy the same
  application in varying environments.
• Chosen a particular environment, the architect
  select appropriate technologies and fine tunes
  the construction patterns
• The desired degree of performance, scalability
  and security can be specified
• IBM Rational Rapid Developer creates an optimized
  code for each deployment model
• IBM Rational Rapid Developer can now be used for
  functional and performance testing
• Each stage can be iterated

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Deployment models
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Rational toolset

• In addition to IBM Rational Rapid Developer
  (6,595)
• IBM Rational RequisitePro (2,034)
• IBM Rational XDE (1,595)
• IBM Rational Rose
• IBM Rational ClearCase (65,950 for a 10-user
  license)
• IBM Rational ClearQuest
• IBM Rational TeamTest

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References

• RAD
• www.gantthead.com/process/processMain.cfm?ID2-195
  16-2
• sysdev.ucdavis.edu/WEBADM/document/rad_toc.htm
• ARAD
• www.ibm.com
• www-106.ibm.com/developerworks/rational/library/44
  1.htmlN10269