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Rad model

  1. RAD and ARAD Barbara Tacchino
  2. 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
  3. 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
  4. 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 customer’s business has fundamentally changed by the time the system is ready for use  Satisfying the customer at the time of delivery
  5. 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)
  6. 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
  7. RAD development cycle
  8. 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”
  9. 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 system’s scope  a cost justification for the new system
  10. 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
  11. 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
  12. 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
  13. 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
  14. 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
  15. 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
  16. 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
  17. 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
  18. 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
  19. 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
  20. 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
  21. 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
  22. 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
  23. 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
  24. 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
  25. 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
  26. 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
  27. A business application scenario  Let’s use the ARAD process to design this marketplace application
  28. 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
  29. 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
  30. 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
  31. 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
  32. 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
  33. 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
  34. Deployment models
  35. 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®
  36. References  RAD    ARAD  