The web application development process

The web application development processBasharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.1Summary of the last lectureWeb engineering extends Software Engineering to Web applicationsWhy web engineering?Web applicationsCategories of web applicationsCharacteristics of web applicationsBasharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.2OutlineBasharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.3Development Process modelsoftware development process activitiesRequirement for a web development process modelRational unified process model (RUP)suitability for web application development1. Process modelBasharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.4A set of related activities that leads to the production of a software productdevelopment of software from scratchextending and modifying existing systemsCommon activitiesSoftware specificationDesigning and implementationSystem validationSystem evolution1.1 Process activitiesBasharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.5Software specification: The functionality of the software and constraints on its operation must be definedcritical stage (can lead to problems in design and implementation)Activities:Feasibility studyRequirement elicitation and analysisRequirement specificationRequirement validation1.1 Process activitiesBasharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.6Software design and implementation: Design is the description ofSystem structureData modelsInterface between componentsImplementation: Converting a system specification into an executable system1.1 Process activitiesBasharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.7System validation: Intended to show that the system confirms its specificationmeets customer’s expectationsDevelopment testingtested by the people developed the componentsSystem testingfinding component integration errorsAcceptance testingSystem is tested by the customer’s provided data1.1 Process activitiesBasharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.8Software evolution:Software is flexible as compared to hardware Changes can be made to the system during development or after the development1.2 Common approachesBasharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.9The waterfall approachIterative approachReuse oriented approach 2. Requirements for a web application development processEvolving from informational medium to application mediumExisting approaches are over-pragmaticlead to short development timeWeb engineering does not have its own mature development process modelSE development process models are adoptedBasharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.102. Requirements for a web application development processBasharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.11Handling Short development cyclesDevelopment time is shortNormally does not exceed six monthImmediate delivery mechanismCapture share in the marketLeaves less freedom for systematic development process2. Requirements for a web application development processBasharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.12Handling changing requirementRequirements often emerge during developmentas developer understand the unknown businessIntegrate changes rapidly to remain in competitionUser involvement is more criticaldue to emerging and unstable requirements2. Requirements for a web application development processBasharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.13Reuse and integrationto meet time constraints developer try to reuse componentsLeads to integration issuesDevelopment can not be isolated from the development of other applications within the organization2. Requirements for a web application development processBasharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.14Adapting to web application’s complexity levelprocess depends upon the level of complexityprocess is adapted dynamicallyfor low complexity, it should be like lightweight processfor high complexity, it should be like heavyweight process3. Rational unified processRUP is a heavyweight, phase oriented, incremental and iterative processDescribed in three perspectivesDynamic perspective: phasesStatic perspective: activities in phasesPractice perspective: good engineering practicesBasharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.153. Rational unified processBasharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.16RUP phases:Inception: Define the business case for the projectGoals:Business caseIdentify and interact with external entitiesAsses the business contributionArtifacts:business case3. Rational unified processBasharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.17RUP phases:Elaboration: establish understanding with the problemGoals:Establish software scopeDiscriminating critical use-casesEstimating cost, schedules and risksArtifacts:development plan, use-case model, architectural description3. Rational unified processBasharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.18RUP phases:Construction: involves system design, programming and testingGoals:Develop the design Implement the designValidate the systemArtifacts:System, training material3. Rational unified processBasharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.19RUP phases:Transition: Installing the system in real environmentGoals:Testing in real environment trainingBug fixing, performance enhancementsArtifacts:A documented system working correctly3. Rational unified processBasharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.20RUP activities (workflows):Requirementsanalysisdesignimplementationtest3. Rational unified processBasharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.21RUP good practices:Develop software iterativelyManage requirementsUse component-based architecturesVisually model software-using UMLVerify software qualityControl changes to software3. Rational unified processBasharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.22activitiesphases3.1 RUP for web applicationBasharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.23Inception phase:Definition is problematic for web applicationno concrete view of the system at beginninghas target group but needs are unknownElaboration phase:due to short development time, first version has priority over clearly defined end-product 3.1 RUP for web applicationBasharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.24Construction phase:exists in web development processTransition phase:is meaningful for web application development3.1 RUP for web applicationBasharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.25Handling short development cycles:Conflictingshort cycle means concession in modeling and documentation while RUP is heavyweightHandling changing requirements:Conflicting with time constraintsrequire concrete vision at the end of inception phase which require more time in web application due to evolving requirements3.1 RUP for web applicationBasharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.26Parallel development of different releases:can be met with RUPRUP only allow parallel development in construction phaseReuse and integration:ConflictingIt requires coordination with development processes of other applications RUP does not describe this 3.1 RUP for web applicationBasharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.27Adapting to a Web application’s complexity level:RUP can be adopted for later stages when complexity of web application is understoodSummaryBasharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.28Development Process modelsoftware development process activitiesconventional software development approachesRequirement for a web development process modelRational unified process model (RUP)suitability for web application developmentReferencesChapter 10, Kappel, G., Proll, B. Reich, S. & Retschitzegger, W. (2006). Web Engineering, Hoboken, NJ: Wiley & SonsChapter 2, Sommerville, Software Engineering, ISBN-10: 0-13-703515-2 , PEARSON Basharat Mahmood, COMSATS Institute of Information Technology, Islamabad, Pakistan.29