Prototyping and Rapid                                            Contents
                       Application Development (RAD)
                                                                                        aDefinitions
                       2 steps forward, 1 step back?                                    aAnecdotal advantages!
                                                                                        aAnecdotal problems!
                       Jeremy Reece - School of Computing                               aSurvey evidence
                                   University of Wolverhampton                          aOur experiences
                                                                                        aSummary
                       email: JPR@wlv.ac.uk                                             aReferences
                                         Prototyping and Rapid                                             Prototyping and Rapid Application 
                                       Application Development (RAD)    1                                     Development (RAD)               2
                   RAD - Background                                                     What is RAD 
                    aTopical in 1990’s after                                            aRAD is
                       `Book Rapid Application Development by Martin, J (1991)             `a complete methodology covering systems development from 
                    aBecame latest buzz phrase                                               business requirements to ongoing development (not 
                                                                                             maintenance)
                    aFurther books
                    aSupport tools to facilitate it                                        `a ‘tool kit’ methodology
                    aDSDM 
                       `consortium of leading industrial names                             `Open, can be adapted to projects, individual and organisational 
                       `have produced a RAD method                                           philosophy
                    aMany techniques used have been around for a long time                 `can utilise a wide range of techniques and tools
                       `recently brought forward as solutions to IS problems.
                                      Prototyping and Rapid Application                                    Prototyping and Rapid Application 
                                          Development (RAD)               3                                   Development (RAD)               4
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                     RAD - Goals                                                                RAD - Quality
                     aRadically changes way systems are developed with goals                    The definition of quality in a RAD environment is put well by 
                        of.                                                                     James Martin
                         `High quality systems                                                     “meeting the true business (or user) requirements as 
                         `fast development and delivery                                         effectively as possible at the time the system comes into 
                         `low costs                                                             operation”
                                                  High              High                                                                 (Martin 1991)
                         `These should            Speed            Quality                      as opposed to:
                           go hand in hand 
                           when the right tools            Low
                           and techniques are used         Cost                                    “conforming to the written specification as effectively as 
                                                                        Martin, J.1991          possible”
                                                                                                                                         (Martin 1991)
                                          Prototyping and Rapid Application                                         Prototyping and Rapid Application 
                                              Development (RAD)                 5                                        Development (RAD)                 6
                     RAD - Properties                                                           RAD - Cost
                         `Does away with the concept of a frozen specification                  aEmphasis placed on low cost
                                                                                                    `All developments should be cost effective though
                         `Place emphasis on user involvement and                                    `identified as potential expensive option in terms of up front 
                           responsibility throughout whole development                                investment (Graham 1995a)
                         `Properties                                                            aOrganisation may pay more for a quality system in a 
                                                                                                   shorter time-scale
                            ⌧Must be delivered in 2 - 6 months
                            ⌧split into increments if too large to enable this,                 aEvidence all goals are achievable including lowering of 
                            ⌧each increment is implemented separately with frequent delivery of 
                              working parts of system.                                             costs (Goodwin 1993)
                                          Prototyping and Rapid Application                                         Prototyping and Rapid Application 
                                              Development (RAD)                 7                                        Development (RAD)                 8
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                       Rapid Development                                                                  RAD - Traditional Methodologies
                                             Rapid Development                                            aGoals of RAD diametrically opposed to more traditional 
                                                                                                             methodologies which adopt a waterfall model
                       Small Teams     Reusable parts         Automated tools    User
                                                                                 Involvement              aAlthough quality and speed of delivery are paramount, 
                                                                                                             does not mean what is good in traditional system 
                               Lower Cost              Higher           Meets business                       development is thrown away. There must be
                                                       Quality          needs better                          `Effective project management            testing
                                                                                                              `appropriate up to date documentation    quality assurance
                                                           Lower maintenance                                  `requirements specification              designs
                                                                 costs                                        `appropriate maintainability             reuse etc
                      Rapid development, high quality and lower costs go hand in hand if an appropriate development
                      methodology is used, Martin 1991
                                              Prototyping and Rapid Application                                                 Prototyping and Rapid Application 
                                                  Development (RAD)                      9                                           Development (RAD)                    10
                       RAD - Traditional Methodologies                                                    RAD - Applicability to 
                       (Cont’d)                                                                           Organisations
                        aDSDM manual (1995) emphasises systems must be build                              aRAD is more applicable to organisations because
                          on sound s/w engineering principles                                                 `World market place is competitive, need right system at the 
                                                                                                                right time to get competitive edge
                        aKey difference                                                                       `Organisations are dynamic and evolving, requirements change 
                                                                                                                as a system is built, a frozen specifications become outdated
                           `these issues are not allowed to dominate business requirements                    `IT now viewed as a cost centre not a resource, once system 
                              and speed of delivery                                                             delivered it starts earning money
                           `must be appropriate to project needs                                              `Systems are used by users, if jointly developed by users then 
                           `e.g. a system with a lifetime of 3 months shouldn’t take 18                         more likely to be accepted
                              months to develop
                                              Prototyping and Rapid Application                                                 Prototyping and Rapid Application 
                                                  Development (RAD)                     11                                           Development (RAD)                    12
                                                                                                                                                                                         3
                     The DSDM View                                                            DSDM Principles
                     aA product based view of development is more flexible                     aDevelopment teams - consist of developers and users 
                        than an activity based view                                              who are empowered to make decisions
                                                                                               aBusiness requirements paramount
                     aInteractive development is important to developing                       aDevelopers and users communicate closely through 
                        systems rapidly                                                          iterative development involving prototypes
                                                                                               aChange is encouraged and is reversible
                     aRapid application development must involve user                          aAll involved must be highly skilled and motivated 
                        involvement                                                              towards business objectives
                                                                                               aTesting is done throughout development and reviewed 
                     An attempt to provide a framework/method (DSDM 1995)                        by whole team
                                         Prototyping and Rapid Application                                         Prototyping and Rapid Application 
                                             Development (RAD)                13                                       Development (RAD)                14
                     DSDM Principles (Cont’d)                                                 RAD - Usage
                     aLarger projects - frequent deliverables should be                        aMay be based upon tools and techniques found in other 
                        scheduled                                                                methodologies
                     aHigh level scope and purpose of the system should be                     aHence can be superimposed on existing skills
                        agreed and fixed early in development                                     `although easier for some than others
                     aRelationship between vendor and purchaser must be                        aGoals and Principles enforce changes in
                        one of co-operation.                                                      `project structure
                                                                                                  `project management
                                                                                                  `team organisation and motivation
                                                                                                  `philosophy and
                                                                                                  `working practice
                                                                                               aAll left is modeling tools and some techniques
                                         Prototyping and Rapid Application                                         Prototyping and Rapid Application 
                                             Development (RAD)                15                                       Development (RAD)                16
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