An Introduction to Web Engineering

135327_3Week1.pdf

An Introduction to Web

Engineering

Week 1

SyllabusSyllabus

•htt p : // www.csun.edu / ~twan g/

595WEB

/ S y llab p// / g/ /y us

Introduction SessionIntroduction

Session

It dlf

• I n t ro d uceyourse lf -Name,majors,expertise,experiences,keywordsrelatedto webengineeringweb  engineering . Software Project Success RateSoftware Project Success Rate Data on 280,000 projects completed in 2000 -Standish Group Data

Definition of Software EngineeringDefinition

of

Software

Engineering

•So f twareEn g ineerin g isde f inedasthe fgg f applicationofscienceandmathematicsby whichtheca p abilitieso f com p utere q ui p ment pfp qp aremadeusefultomanviacomputerp ro g rams , p rocedures , andassociated pg ,p,documentation .

A Survey by the Cutter ConsortiumA

Survey

by the

Cutter

Consortium

•ThetopproblemareasoflargeͲscaleWeb applicationprojects -Failuretomeetbusinessneeds(84%)-Projectscheduledelays(79%) -Budgetoverrun(63%)

Lkffilii(53%)

- L ac k o f f unct i ona li t i es (53%) -Poorqualityofdeliverables(52%)

Definition ofWeb EngineeringDefinition

of Web

Engineering

•WebEn g ineerin g isthea pp licationo f ggppf systematicandquantifiableapproaches( conce p ts , methods , techni q ues , tools ) tocos t Ͳ ( p, ,q,) effectiverequirementsanalysis,design, im p lementation , testin g , o p eration , and p,g ,p, maintenanceofhighͲqualityWebapplications.

Chapter1:Web

-

Based Systems

Chapter

1: Web Based

Systems

•IntheearlydaysoftheWeb,webuiltsystemsusinginformality,urgency,intuition,andart

Informality

leadstoaneasyworkenvironment oneinwhich -

Informality

leads  to  an  easy  work  environment - one in  which youcandoyourownthing. -Urgencyleadstoactionandrapiddecisionmaking. -

Intuition

isanintangiblequalitythatenablesyouto " feel " your -

Intuition

is an  intangible  quality  that  enables  you  to  feel  your waythroughcomplexsituations. -Artleadstoaestheticformandfunction - tosomethingthat p leasesthosewhoencounterit. p •Problemis - thisapproachcanandoftendoes leadtoproblemslead  to  problems

TheWebThe

Web •Anindispensabletechnology -Invirtuallyeveryaspectofmodernliving •Atransformativetechnology -Changesthewaywedothings-

Changesthewayweacquireanddisseminateinformation

•Anevolvingtechnology•Bottomline - highimpactoneveryoneinthe modernworldmodern  world

WebAppsWebApps

•ThetermWebapplication(WebApp) encompasses: -everythingfromasimpleWebpagethatmighthelpa consumercomputeanautomobileleasepaymenttoa comprehensivewebsitethatprovidescompletetravelcomprehensive  website  that  provides  complete  travel  servicesforbusinesspeopleandvacationers. -

Includedwithinthiscate

g or y arecom p letewebsites , gyp, specializedfunctionalitywithinwebsites,andinformationͲ processingapplicationsthatresideontheInternetoronanIntranetorExtranetan 

Intranet

 or 

Extranet

.

WebApp

Attributes

WebApp

Attributes

•Networkintensiveness•

Concurrency

•Contentsensitive•

Continuousevolution

•

Concurrency

•Unpredictableload •

Continuous

evolution •Immediacy •Performance•Security•Availability •

Datadriven

•Aesthetics Data driven

WebApp

Types

WebApp

Types •Informational•TransactionͲoriented•Download

Ct ibl

•ServiceͲoriented Ptl • C us t om i za bl e •

Interaction

• P or t a l s •

Databaseaccess

Interaction

•Userinput

Database

access •Datawarehousing TY

UBIQUITOUS

OMPLEXI

COLLABORATIVE

SOCIAL

WEB •Location-Aware Service •Multi-Platform Delivery •Customized Service

SEMANTIC

WEB •Knowledge Management •Recommender System •Syndication CO

WORKFLOW-BASED

•Chat room •E-Learning Platform •P2P-Service

SOCIAL

WEB •Virtual Shared Workspace •Collaborative Filtering •Weblogs

TRANSACTIONAL

•Online Banking •Online Shopping

Booking System

•E-Government •B2B Solution •Patient Workflow

PORTAL-ORIENTED

•Community-Portal •Online Shopping Mall •Business Portal

INTERACTIVE

•Virtual Exhibition •News Site •Travel Planning •

Booking System

DOCUMENT-CENTRIC

•Static Homepage •Web Radio •Company Web Site

DEVELOPMENT HISTORY

Categories of Web Applications

WhyWeb Engineering?Why

Web

Engineering?

•AsWebApps becomelargerandmorecomplex, -Informalityremains,butsomedegreeofrequirements gatheringandplanningarenecessarygathering  and  planning  are  necessary -Urgencyremains,butitmustbetemperedbyarecognitionthatdecisionsmayhavebroadconsequences- IntuitionremainsbutitmustbeaugmentedbyprovenIntuition remains , but  it  must  be  augmented  by  proven managementandtechnicalpatterns -Artremains,butitmustbecomplementedwithsoliddesign •Bottomline: -wemustadapttheoldͲschoolapproachtotherealitiesofaWeb2.0world

Chapter 2:

WebEngineering

Chapter

2: Web

Engineering

•Wedefineitthisway: - anagile,yetdisciplinedframework f orbuildingindustryͲ qualityWebApps. •Wemustunderstandthemeaningof: -Agile-Disciplinedframework -Industryquality

Why Agility?Why

Agility?

•

BusinessstrategiesandruleschangerapidlyBusiness

strategies  and  rules  change  rapidly •ManagementdemandsnearͲinstantaneous i(hhdd respons i veness ( evenw h ensuc h d eman d sare completelyunreasonable •Stakeholdersoftendon'tunderstandthe consequencesoftheWebandkeepchangingtheir mindevenastheydemandrapiddelivery •An ag il e app r oac hh e l ps cope wi t h t hi s fl u i d i ty a n d ag eapp oacepscopettsudtyad uncertainty.

What is an Agile Process?What

is an Agile

Process?

•AgileWebengineeringcombinesaphilosophyanda setofdevelopmentguidelines.Thephilosophy encourages: -customersatisfaction- earlyincrementaldeliveryoftheWebApp -small,highlymotivatedprojectteamsinformalmethods - informal methods -minimalworkproducts- overalldevelopment simplicity . overall development  simplicity . 

What is an Agile Process

?(cont " d) What is an Agile

Process

? (contd) • An agileprocessstressesdeliveryoveranalysisand An agile  process  stresses  delivery  over  analysis  and  design(althoughtheseactivitiesarenot discouraged),andactiveandcontinuous communicationbetweendevelopersandcustomers. •http://agilemanifesto.org/

Underlying Agility Principles

- I

Underlying

Agility

Principles

I •Ourhighestpriorityistosatisfythecustomerthroughearlyand continuousdeliveryofvaluablesoftware. •Welcomechangingrequirements,evenlateindevelopment.Agile processesharnesscontinuouschangeforthecustomer'scompetitiveprocesses  harness  continuous  change  for  the  customer's  competitive  advantage. •Deliverworkingsoftwareincrementsfrequently,fromasoftenasevery fewdaystoeveryfewmonthswithapreferencetotheshorterfew  days  to  every  few  months , with  a  preference  to  the  shorter  timescales. •Businesspeopleanddevelopersmustworktogetherdailythroughoutthe project. •Buildprojectsaroundmotivatedpeople.Givethemtheenvironmentand supporttheyneed,andtrustthemtogetthejobdone.Themostefficient andeffectivemethodofconveyinginformationtoandwithina developmentteamisface to faceconversation development  team  is  face r to r face  conversation .

Underlying Agility Principles

- II

Underlying

Agility

Principles

II •Workingsoftwareistheprimarymeasureofprogress. •Agileprocessespromotesustainabledevelopment.Thesponsors, develo p ers , andusersshouldbeabletomaintainaconstant p ace p,p indefinitely. •Continuousattentiontotechnicalexcellenceandgooddesignenhances a g ilit y . gy •Simplicity - theartofmaximizingtheamountofworknotdone - is essential.• The bestarchitecturesrequirementsanddesignsemergefromself • The  best  architectures , requirements , and  designs  emerge  from  self r organizingteams. •Atregularintervals,theteamreflectsonhowtobecomemoreeffective, thentunesandadjustsitsbehavioraccordinglythen  tunes  and  adjusts  its  behavior  accordingly .

What is aWebE Framework?What

is a WebE

Framework?

•AframeworkisasetofactivitiesthatwillalwaysbeperformedforeveryWebengineeringproject- thoughthenatureoftheactivitiesmi

g htvar y tosuitthe p ro j ect. gypj •Eachframeworkactivityiscomposedofasetofactions i •Act i onsencompass -worktasks -workproducts q alitass rancepointsand - q u alit y ass u rance points , and  -projectmilestones •

Aframeworkalsohasasetof

" umbrellaactivities " A framework  also  has  a  set  of  umbrella  activities

A Generic FrameworkA

Generic

Framework

TheWebE Framework: ActivitiesThe

WebE

Framework:

Activities

•Communication.Involvesheavyinteractionandcollaborationwiththe customer(andotherstakeholders)andencompassesrequirements gatheringandotherrelatedactivities. •Planning.EstablishesanincrementalplanfortheWebEwork. •Modeling.Encompassesthecreationofmodelsthatassistthedeveloper dhbddbdh an d t h ecustomerto b etterun d erstan d We b

Apprequirementsan

d t h e design •Construction.CombinesboththegenerationofHTML,XML,Java,and similarcodewithtestingthatisrequiredtouncovererrorsinthecodesimilar  code  with  testing  that  is  required  to  uncover  errors  in  the  code . •Deployment.DeliversaWebAppincrementtothecustomerwho evaluatesitandprovidesfeedbackbasedontheevaluation.

Adapting the FrameworkAdapting

the

Framework

•Adapttotheproblem,totheproject,totheteam,andtothe organizationalculture •Andcontinuetoadaptthroughouttheprojectascircumstanceschange! •Adaptationleadsto: •Overallflowofactivities,actions,andtasksandtheinterdependenciesamongthem• Degreetowhichworktasksaredefinedwithineachframeworkactivity •

Degree

to  which  work  tasks  are  defined  within  each  framework  activity •Degreetowhichworkproductsareidentifiedandrequired •Mannerinwhichqualityassuranceactivitiesareapplied

•Mannerinwhichprojecttrackingandcontrolactivitiesareapplied•Overalldegreeofdetailandrigorwithwhichtheprocessisdescribed

•Degreetowhichcustomersandotherstakeholdersareinvolvedwiththeproject •Levelofautonomygiventothesoftwareprojectteam • DegreetowhichteamorganizationandrolesareprescribedDegree to  which  team  organization  and  roles  are  prescribed

The Influence of Software EngineeringThe

Influence

of

Software

Engineering

•Quality:fosteracontinuousprocessimprovementculture •Process:the g luethatholdsthetechnolo gy la y ersto g ether ggyyg •Methods:providethetechnicalhowͲto's•

Tools:supportfortheprocessandthemethods

•

Tools:

support  for  the  process  and  the  methods

WebE MethodsWebE

Methods

•Communicationmethods •

RequirementsanalysismethodsRequirements

analysis  methods •Designmethods•Constructionmethods •Testingmethods

What aboutTools andTechnology?What

about Tools and

Technology?

...toolsandtechnolo gy arever y im p ortant , gyyp, butthey'llworkwellonlyifthey'reusedwithin thecontextofanagileframeworkforWebengineeringandinconjunctionwithprovenengineering  and  in  conjunction  with  proven  methodsforunderstandingtheproblem, designingasolution,andtestingitthoroughly.

WebE Best PracticesWebE

Best

Practices

•Takethetimetounderstandbusinessneedsandproductobjectives,even ifthedetailsoftheWebApp arevague. •DescribehowuserswillinteractwiththeWebApp usingascenarioͲbased approach. •Alwaysdevelopaprojectplan,evenifit'sverybrief. •S p endsometimemodelin g whatitisthat y ou're g oin g tobuild. pgygg •Reviewthemodelsforconsistencyandquality. •Usetoolsandtechnologythatenableyoutoconstructthesystemwithas manyreusablecomponentsaspossiblemany  reusable  components  as  possible . •Don'treinventwhenyoucanreuse. •Don'trelyonearlyuserstodebugtheWebApp - designanduse hbflh compre h ensivetests b e f orere l easingt h esystem.

LabActivitiesLab

Activities

•Or g anizeateam. g •Notethateachteamconsistsoffour/five td t s t u d en t s. •

SubmitteaminformationincludingstudentSubmit

team  information  including  student  names,studentIDs,andemailaddresses. (Team)Homework Assignment 1(Team)

Homework

Assignment

1 •Studyassigned(Web1.0and)Web2.0 patterns(seethenextslidesforassignment)patterns  (see  the  next  slides  for  assignment)  andprepareforpresentationslides.

Pttilidhldild

• P resen t a ti ons lid ess h ou ld i nc l u d e, description,casestudy,andvisual tti(fi )fhtt represen t a ti on (fi gure ) o f eac h pa tt ern. •Duedateis7:00pm,January31 st (Team) Homework Assignment 1(cont " d) (Team)

Homework

Assignment

1(contd)

T 1 SOA SS T eam 1 SOA , S aa S Team 2 Participation-Collaboration, Asynchronous Particle Update Team 3 Mashup, RUE, Structured InformationTeam 4 The Synchronized Web, Collaborative Tagging Team 5 Declarative Living and Tag Gardening, Semantic Web (Team)Homework Assignment 2 (Team)

Homework

Assignment

2 •StudyWebEngineeringProcesses(Ch.3or relatedmaterials) and preparefor related  materials)  and  prepare  for  presentationslides. •Presentationslidesshouldinclude,all activitiesandtasksfordevelopingyougroup projects. •Duedateis7:00 p m,Januar y 31
st py