【正文】 rmination ? Developing a standard for software process assessment ? ISO joint mittee, Europe, Australia – IEEE 1074, IEEE 12207 Product Assessment ? Reviews, inspections, walkthroughs of Plans, reports, models, standards – Project management, quality assurance, training, test plan(s) – Requirements, analysis, architecture, detailed design model, test cases – Issue or problem reports – Metric reports – Traceability reports – Documentation, coding standards – … Software Reviews ? They may include managerial reviews, acquirersupplier reviews, technical reviews, inspections, walkthroughs, and audits. ? Inspection: – A formal evaluation technique in which an artifact (., software requirements, design, or code) is examined in detail by a person or group other than the originator – detect faults, violations of development standards, and other problems. – review members are peers (equals) of the designer or programmer. – data is collected during inspections for later analysis and to assist in future inspections. Problem Reporting, Tracking, and Resolving ? Describe the practices and procedures to be followed for reporting, tracking, and resolving problems – Who can report a problem? – How is it reported? – How is it tracked? – Who determines if it is a problem that going to be resolved? – How is it assigned for resolution? – How does the person indicate it has been corrected? – Who reviews it to determine if it can be closed? ? Problems can be product or process related – . incorrect requirement, inplete class definition, code defect, ambiguous description in user documentation, process to review detailed design is not clearly defined, etc. SQA: 6 SIGMA QUALITY ? Sigma = “ Standard Deviation” ? Typical software has 3 to 4 defects per KLOC ? 6 Sigma = 3 to 4 defects per million lines of code ? Average panies accept % quality = 4S ? 6 Sigma = % level of quality SQA: 6 SIGMA QUALITY ? Quality Improvements: – 3Sigma to 4Sigma = 10 fold – 4Sigma to 5Ssigma = 30 fold – 5Sigma to 6Sigma = 70 fold ? BestinClass panies in some industries operate at 6Sigma (Airline = 。 :1) ? Software anizations need to assess this SQA: Quality Software People Process Management Discipline SQA SQA: Pursuing SQA What anizations are doing – Nothing (42%) – Slogans(口號 ) “ Quality is Job One!” (4%) – Improved testing (24%) – Focus on defect prevention (20%) – Process Improvements (9%) – Other... (1%) SQA: Software Reliability (MTBF) Putnam’ s Software Reliability Model E R R O R S 0 N U M B E R O F T I M E Operational Capability 0 SQA: Pursuing SQA the Deming Way ? Purpose includes improvement ? Quality philosophy ? Eliminate mass inspections ? Award business based on more than price ? Continuous improvement ? Institute OJT(On the job training) ? Institute Leadership ? Drive out fear ? Break down barriers ? Eliminate slogans ? Eliminate numerical quotas goals ? Remove barriers to pride of workmanship ? Institute education and selfimprovement ? Get everyone involved SQA: Strategy by Yourdon If management or customer says... – Speed up testing...just say NO! – Don’ t worry about a few bugs...just say NO! – We’ ll pin down the specs later...just say NO! – Don’ t worry, its just a beta version...just say NO! – I don’ t care if there are bugs, get it out the door...just say NO! Summary ? Software quality generally means fitness for purpose – need to know what that purpose is… – …what functions must it perform – …what other properties must it have (. modifiability, reliability, usability…) ? Not all quality attributes can be measured during design – because quality is not an attribute of software in isolation – but we can look for predictors ? Reliability, efficiency, maintainability, usability – are usually the four most important quality factors – …although different authors give different lists ? Modularity is often a good predictor of quality – measure it by looking at cohesion and coupling 謝謝觀看 /歡迎下載 BY FAITH I MEAN A VISION OF GOOD ONE CHERISHES AND THE ENTHUSIASM THAT PUSHES ONE TO SEEK ITS FULFILLMENT REGARDLESS OF OBSTACLES. BY FAITH I BY FAITH