Quality Management, & Agile Methods Quality Management

Quality Management,& Agile MethodsQuality ManagementBeatrice Åkerblombeatrice@dsv.su.seWhat is quality?!Quality, simplistically, means that aproduct should meet its specification.!This is problematical for softwaresystems There is a tension between customerquality requirements (efficiency,reliability, etc.) and developer qualityrequirements (maintainability,reusability, etc.) Some quality requirements are difficultto specify in an unambiguous way Software specifications are usuallyincomplete and often inconsistent3The qualitycompromise!We cannot wait for specifications toimprove before paying attention toquality management.!We must put quality managementprocedures into place to improve qualityin spite of imperfect specification.4

Scope of qualitymanagement!!!Quality managementactivitiesQuality management is particularlyimportant for large, complex systems.!Quality assurance The quality documentation is a record ofprogress and supports continuity ofdevelopment as the development teamchanges!For smaller systems, qualitymanagement needs less documentationand should focus on establishing aquality culture.!Quality planning Select applicable procedures andstandards for a particular project andmodify these as required.Quality control !Establish organisational proceduresand standards for quality.Ensure that procedures and standardsare followed by the softwaredevelopment team.Quality management should be separatefrom project management to ensureindependence.56Process-based qualityProcess-based quality!Define processDevelopproductImproveprocessMore complex relation for softwarebecause: The application of individual skills andexperience is particularly important insoftware development External factors such as the novelty ofan application or the need for anaccelerated development schedulemay impair product qualityAssess re must be taken not to imposeinappropriate process standards - thesecould reduce rather than improve theproduct quality8

Principal productquality factorsDevelopmenttechnologyProcess qualityProductqualityPractical processquality!Define process standards such as howreviews should be conducted,configuration management, etc.!Monitor the development process toensure that standards are being followed!Report on the process to projectmanagement and software procurerPeople qualityCost, time &schedule!910Quality assuranceand standardsProduct and processstandardsStandards are the key to effective qualitymanagement Product standards definecharacteristics that all componentsshould exhibit e.g. a commonprogramming styleProcess standards define how thesoftware process should be enacted11Product standardsProcess standardsDesign review formDesign review conductRequirements document structureSubmission of documents to CMMethod header formatVersion release processJava programming styleProject plan approval processProject plan formatChange control processChange request formTest recording process12

Standardsdevelopment!!!ISO 9000!An international set of standards forquality management.!Review standards and their usageregularly -- standards can quicklybecome outdated and this reduces theircredibility amongst practitionersApplicable to a range of organisationsfrom manufacturing to service industries.!ISO 9001 applicable to organisationswhich design, develop and maintainproducts.Detailed standards should haveassociated tool support!ISO 9001 is a generic model of thequality process that must be instantiatedfor each organisation using the standard.Involve practitioners in development.Engineers should understand therationale underlying a standard1314ISO 9000 certificationISO 9000 and qualitymanagement!Quality standards and proceduresshould be documented in anorganisational quality manual!An external body may certify that anorganisation!s quality manual conformsto ISO 9000 standards!Some customers require suppliers to beISO 9000 certified although the need forflexibility here is increasingly recognisedISO 9000quality modelsinstantiated asdocumentsOrganisationquality manualis used to developProject 1quality planinstantiated asProject 2quality planProject 3quality planSupports15Organisationquality process16Project qualitymanagement

Documentationstandards!!Particularly important - documents arethe tangible manifestation of thesoftwareDocumentation process standards !Document standards !Concerned with how documentsshould be developed, validated andmaintainedConcerned with document contents,structure, and appearanceDocument interchange standards DocumentationprocessCreateinitial draftStage 1:CreationProofreadtextStage ewdraftApproved documentProducefinal draftCheckfinal draftApproved documentReviewlayoutProduceprint mastersConcerned with the compatibility ofelectronic documents18Document standardsQuality planningDocument identification standards !!A quality plan sets out the desiredproduct qualities and how these areassessed and defines the mostsignificant quality attributes!The quality plan should define the qualityassessment process!It should set out which organisationalstandards should be applied and, wherenecessary, define new standards to beusedHow documents are uniquely identifiedStandard structure for projectdocumentsDocument presentation standards !!Document structure standards Define fonts and styles, use of logos,etc.Document update standards PrintcopiesStage 3:Production17!Re-draftdocumentDefine how changes from previousversions are reflected in a document1920

Software qualityattributesQuality reviews!This is the principal method of validatingthe quality of a process or of a product!A group examines part or all of aprocess or system and itsdocumentation to find potential ilityResilienceModularityEfficiencyThere are different types of review withdifferent objectivesRobustnessComplexityLearnability Inspections for defect removal(product) Reviews for progress assessment(product and process) Quality reviews (product andstandards)!!2122Softwaremeasurement andmetricsSoftware metric!Software measurement is concernedwith deriving a numeric value for anattribute of a software product orprocessThis allows for objective comparisonsbetween techniques and processesAny type of measurement which relates toa software system, process or relateddocumentation Lines of code in a program, the Fogindex, number of person-days requiredto develop a component.!Allow the software and the softwareprocess to be quantified!May be used to predict product attributesor to control the software process!Product metrics can be used for generalpredictions or to identify anomalouscomponentsCovered on the course TEME/ID20032324

Internal and externalattributesThe measurementprocess!A software measurement process maybe part of a quality control process!Data collected during this processshould be maintained as anorganisational resource!Once a measurement database hasbeen established, comparisons acrossprojects become possibleNumber of procedureparametersMaintainabilityCyclomatic complexityReliabilityProgram size in linesof codePortabilityNumber of errormessagesUsabilityLength of user manual!Data accuracyMeasurementanalysisThe questions to be answered shouldbe decided in advance and therequired data identifiedTell people why the data is beingcollected !26Don!t collect unnecessary data !25It should not be part of personnelevaluation!It is not always obvious what datameans Analysing collected data is very difficult!Professional statisticians should beconsulted if available!Data analysis must take localcircumstances into accountDon!t rely on memory Collect data when it is generated notafter a project has finished2728

Process improvement!Process Improvement!Understanding existing processes andintroducing process changes to: improve product quality reduce costs accelerate schedulesMost process improvement work so farhas focused on defect reduction. Thisreflects the increasing attention paid byindustry to quality30The processimprovement cycleProcess improvementstages!Process measurement Measure!Process analysis ChangeAnalyse!The current process is assessed andbottlenecks and weaknesses areidentifiedProcess change 31Attributes of the current process aremeasured. These are a baseline forassessing improvementsChanges to the process that havebeen identified during the analysis areintroduced32

Principal productquality factorsDevelopmenttechnologyProcess qualityProductqualityPeople qualityQuality factors!For large projects with “average”capabilities, the development processdetermines product quality.!For small projects, the capabilities of thedevelopers is the main determinant!The development technology isparticularly significant for small projects!In all cases, if an unrealistic schedule isimposed then product quality will sufferCost, time &schedule3334Process classificationProcess applicability!Informal !PrototypesShort-lifetime systems4GL business systemsSmall/medium-sizedsystemsDefined process model which drivesthe development processManagedprocessLarge systemsLong-lifetime n domainsRe-engineered systemsMethodical !InformalprocessManaged !No detailed process model.Development team chose their ownway of workingProcesses supported by somedevelopment method such as the RUPSupported Processes supported by automatedtools3536

Process choice!!!!Process tool supportProcess used should depend on type ofproduct which is being developed For large systems, management isusually the principal problem so youneed a strictly managed process For smaller systems, more informalityis possibleThere is no uniformly applicable processwhich should be standardised within anorganisation High costs may be incurred if you forcean inappropriate process on adevelopment team Inappropriate methods can alsoincrease costs and lead to ProjectmanagementtoolsAnalysis anddesignworkbenches3738ProcessmeasurementProcess changeImprovingprocessSpecialisedtoolsWherever possible, quantitative processdata should be collected!Involves making modifications to existingprocesses !This may involve:However, where organisations do nothave clearly defined process standardsthis is very difficult as you don!t knowwhat to measure. A process may haveto be defined before any measurementis possibleProcess measurements should be usedto assess process improvements But this does not mean thatmeasurements should drive theimprovements. The improvement drivershould be the organisational objectives39! Introducing new practices, methods orprocesses Changing the ordering of processactivities Introducing or removing deliverables Introducing new roles orresponsibilitiesChange should be driven by measurablegoals40

Process changestages!Improvement identification!Improvement prioritisation!Process change introduction!Process change training!Change tuning!The SEI!s mission is to promote softwaretechnology transfer particularly to USdefence contractors!It has had a profound influence onprocess improvement Capability Maturity Model introduced inthe early 1990s Revised maturity framework (CMMI)introduced in 2001Problems with theCMM!InitialPractices associated with model levels Essentially uncontrolledRepeatableProduct management proceduresdefined and usedDefined!Process management procedures andstrategies defined and usedManaged !!The SEI capabilitymaturity model !The CMMI framework is the currentstage of work on process assessmentand improvement that started at theSoftware Engineering Institute in the1980s42 !!41 !The CMMI frameworkQuality management strategies definedand usedOptimising Discrete rather than continuous !Companies could be using practicesfrom different levels at the same timebut if all practices from a lower levelwere not used, it was not possible tomove beyond that levelDid not recognise distinctions betweenthe top and the bottom of levelsPractice-oriented Concerned with how things were done(the practices) rather than the goals tobe achievedProcess improvement strategiesdefined and used4344