Software Architecture Adaptability

Software Architecture Adaptability

اسلاید 1: Nary SubramanianFirmware EngineerApplied Technology DivisionAnritsu CompanyRichardson, TX.Email: narayanan.subramanian@anritsu.comLawrence ChungDept. Of Computer ScienceUniv. Of Texas at DallasRichardson, TX.Email: chung@utdallas.eduSoftware Architecture Adaptability: An NFR Approach

اسلاید 2: Software Architecture Adaptability: An NFR ApproachJini and the Programmer*Once a lucky and broad-minded programmer found a Jini.Programmer: “I feel sorry for people in the mid-east. Can you fix that problem so that no more suffering occurs?”Jini: “I am sorry, but that is something I cannot do.”Programmer: “Then will you fix my programs so that they meet the needs of every single user?”Jini: “Give me the map - I have a better chance at Middle East!” *source: Web Moral : Be Adaptable

اسلاید 3: Software Architecture Adaptability: An NFR Approachdual-mode cell phonecommand-processing system that accepts commands of different versionssoftware system being able to operate on different OS’sself-managing systems such as eLiza dynamic uploading of firmwareAdaptability Examples

اسلاید 4: accomodate new requirements easilyfaster development of new softwareadding new software featuresfixing defects during maintenance phase (which consumes currently 50% of cost)Software Architecture Adaptability: An NFR ApproachAdvantages of Adaptable Systems

اسلاید 5: No fixed definitionExamples:ease with which system may be adapted to changing requirementsmodifies behavior in response to changes in operating environmenta software quality metric...and many more ...Software Architecture Adaptability: An NFR ApproachWhat is Adaptability?

اسلاید 6: Software Architecture Adaptability: An NFR ApproachCurrent Approach to AdaptabilityState Problem“problem is to develop adaptable system that does xxx ...”Define Adaptability“adaptability is evolution to meet the needs of user and business”Develop solution“Solution”

اسلاید 7: Lack of traceability of solutions to requirements : why should “Solution” be adaptable? The usual justification is “Solution does so-and-so and hence satisfies definition of adaptability”.No way to analyze/explore alternative solutions: what are other possibilities besides “Solution”No way to determine the degree to which system is adaptableSoftware Architecture Adaptability: An NFR ApproachSome Drawbacks of Current Approach

اسلاید 8: Applicable to any definition of adaptabilityAllows alternative solutions to be exploredDecomposes “adaptability” depending on the domain Criticalities can be allocated to different NFRs of the decompositionPermits design tradeoffsAssessment of adaptability is possibleSoftware Architecture Adaptability: An NFR ApproachThe NFR Approach

اسلاید 9: Software Architecture Adaptability: An NFR ApproachSteps in The NFR ApproachDecompose Adaptabilityfor the domain - NFR softgoal hierarchyDevelop architectural alternatives - Design softgoal hierarchyDetermine extent to whichdesign softgoals satisfice NFR softgoals - claim softgoal hierarchyAssign criticalities to various softgoalsChoose the design components that satisfice the relevant softgoalsLegend: Down arrow = go to next step; Up arrow = iterate

اسلاید 10: Software Architecture Adaptability: An NFR ApproachA Comprehensive Definition of AdaptabilityLegend:S,S’: old and new system E,E’: old and new environmentS,E: change in system, environment

اسلاید 11: Software Architecture Adaptability: An NFR ApproachExample SIG Development - Step 1 NFR Softgoal DecompositionSIG = Softgoal Interdependency Graph

اسلاید 12: Software Architecture Adaptability: An NFR ApproachExample SIG Development - Step 2 Design Softgoal DecompositionSIG = Softgoal Interdependency Graph

اسلاید 13: Software Architecture Adaptability: An NFR ApproachFinal SIG SIG = Softgoal Interdependency Graph

اسلاید 14: Software Architecture Adaptability: An NFR ApproachNotation for SIGsNFR SoftgoalDesign SoftgoalOR-contributionAND-contributionStrongly-negatively satisficingNegatively satisficingPositively satisficingStrongly-positively satisficingCorrelation Rule (negatively satisficing)

اسلاید 15: A KB of design goals, decomposition methods, correlations will make it easier to search for such items for future use.Currently even when such catalogs are available, they are not easy to use.NFR Approach allows for a knowledge-based approachCan be used to (semi-)automatically generate adaptable architecturesSoftware Architecture Adaptability: An NFR ApproachKnowledge-Based Approach

اسلاید 16: Software Architecture Adaptability: An NFR ApproachFrame-like NotationsDesign SoftgoalNFR Decomposition Method

اسلاید 17: Software Architecture Adaptability: An NFR ApproachFrame-like Notations (cont’d)Operationalization MethodCorrelation Rule

اسلاید 18: Analysis of NFR adaptabilityCurrent techniques are not traceable to “whys” of softwareNFR Approach provides several advantages to developing adaptable architecturesNFR Approach allows for a KB approach which will help generate architectures (semi-)automatically.Software Architecture Adaptability: An NFR ApproachSummary

اسلاید 19: Software Architecture Adaptability: An NFR ApproachFuture Work Better cataloging of the NFR Adaptability and its refinements Develop methods for different domains so that KB is more useful to industry Develop procedure to generate architectures.