1 Software Quality Assurance Prof.M.D.Acharya

2 Organization of this Lecture: zIntroduction Quality Engineering. zQuality control and Quality Assurance zISO 9000 zSEI CMM zSummary

3 Introduction zTraditional definition of quality: yfitness of purpose, xa quality product does exactly what the users want it to do.

4 Fitness of purpose zFor software products, yfitness of purpose: xsatisfaction of the requirements specified in SRS document.

5 Fitness of purpose zA satisfactory definition of quality for many products: ya car, a table fan, a food mixer, microwave oven, etc. zBut, not satisfactory for software products.

6 Introduction zConsider a software product: yfunctionally correct, xi.e. performs all functions as specified in the SRS document, ybut has an almost unusable user interface. xcannot be considered as a quality product.

7 Introduction zAnother example: ya product which does everything that users want. ybut has an almost incomprehensible (not able to Understood) and unmaintainable code.

8 Modern view of quality zAssociates several quality factors with a software product : yCorrectness yReliability yEfficiency (includes efficiency of resource utilization) yPortability yUsability yReusability yMaintainability

9 Correctness zA software product is correct, yif different requirements as specified in the SRS document have been correctly implemented. yAccuracy of results.

10 Portability zA software product is said to be portable, yif it can be easily made to work in different operating systems, yin different machines, ywith other software products, etc.

11 Reusability zA software product has good reusability, yif different modules of the product can easily be reused to develop new products.

12 Usability zA software product has good usability, yif different categories of users (i.e. both expert and new users) can easily invoke the functions of the product.

13 Maintainability zA software product is maintainable, yif errors can be easily corrected as and when they show up, ynew functions can be easily added to the product, yfunctionalities of the product can be easily modified, etc.

14 Software Quality Management System zQuality management system (or quality system): yprincipal methodology used by organizations to ensure that the products have desired quality.

15 Quality system zA quality system consists of the following: yManagerial Structure yIndividual Responsibilities. zResponsibility of the organization as a whole.

16 Quality system zEvery quality conscious organization has an independent quality department: yperforms several quality system activities. yneeds support of top management. yWithout support at a high level in a company, xmany employees may not take the quality system seriously.

17 Quality System Activities: zAuditing of projects zDevelopment of: ystandards, procedures, and guidelines, etc. zProduction of reports for the top management ysummarizing the effectiveness of the quality system in the organization. z Review of the quality system itself.

18 Quality system zA good quality system must be well documented. yWithout a properly documented quality system, xapplication of quality procedures become ad hoc, xresults in large variations in the quality of the products delivered.

19 Quality system zAn undocumented quality system: ysends clear messages to the staff about the attitude of the organization towards quality assurance. zInternational standards such as ISO 9000 provide: y guidance on how to organize a quality system.

20 Evolution of Quality Systems zQuality systems have evolved: yover the last five decades. way to produce quality products: xinspect the finished products xeliminate defective products.

21 Evolution of Quality Systems zSince that time, yquality systems of organizations have undergone xfour stages of evolution.

22 Evolution of Quality Systems

23 Evolution of Quality Systems zInitial product inspection method : ygave way to quality control (QC). zQuality control: ynot only detect the defective products and eliminate them ybut also determine the causes behind the defects.

24 Quality control (QC) zQuality control aims at correcting the causes of errors: ynot just rejecting defective products. zStatistical quality control yquality of the output of the process is conclude using statistical methods yin stead of inspection or testing of all products

25 Quality control (QC) zThe next breakthrough, ydevelopment of quality assurance principles

26 Quality assurance zBasic premise of modern quality assurance: yif an organization's processes are good and are followed rigorously, xthe products are bound to be of good quality.

27 Quality assurance zAll modern quality paradigms include: yguidance for recognizing, defining, analyzing, and improving the production process.

28 Total quality management (TQM) zAdvocates: ycontinuous process improvements through process measurements.

29 Business Process reengineering zA term related to TQM. zProcess reengineering goes a step further than quality assurance: yaims at continuous process improvement.

30 Business Process reengineering  Our focus is reengineering of the software process.  Whereas BPR aims at reengineering the way business is carried out in any organization  not just software development organizations.

31 Total quality management (TQM) zTQM goes beyond documenting processes yoptimizes them through redesign. zOver the years the quality paradigm has shifted: yfrom product assurance to process assurance.

32 ISO 9000 zISO (international Standards Organization): ya consortium of 63 countries established to formulate and foster standardization. zISO published its 9000 series of standards in 1987.

33 What is ISO 9000 Certification? zISO 9000 certification: yserves as a reference for contract between independent parties. zThe ISO 9000 standard: yspecifies guidelines for maintaining a quality system.

34 What is ISO 9000 Certification? zISO 9000 specifies: yguidelines for repeatable and high quality product development. yAlso addresses organizational aspects xresponsibilities, reporting, procedures, processes, and resources for implementing quality management.

35 ISO 9000 zA set of guidelines for the production process. ynot directly concerned about the product it self. ya series of three standards: xISO 9001, ISO 9002, and ISO 9003.

36 ISO 9000 zBased on the premise: yif a proper process is followed for production: xgood quality products are bound to follow.

37 ISO 9001: zApplies to: yorganizations engaged in design, development, production, and servicing of goods. yapplicable to most software development organizations.

38 ISO 9002: zISO 9002 applies to: yorganizations who do not design products: xbut are only involved in production. zExamples of this category of industries: ysteel or car manufacturing industries y buy the product and plant designs from external sources: xonly manufacture products. ynot applicable to software development organizations.

39 ISO 9003 zISO 9003 applies to: yorganizations involved only in installation and testing of the products.

40 ISO 9000 for Software Industry zISO 9000 is a generic standard: yapplicable to many industries, xstarting from a steel manufacturing industry to a service rendering company. zMany clauses of ISO 9000 documents: yuse generic terminologies yvery difficult to interpret them in the context of software organizations.

41 ISO 9000 Part-3 zISO released a separate document called ISO 9000 part-3 in 1991 yto help interpret the ISO standard for software industry. zAt present, yofficial guidance is inadequate

42 Why Get ISO 9000 Certification? zSeveral benefits: yConfidence of customers in an organization increases xif organization qualified for ISO 9001 certification. xThis is especially true in the international market.

43 Why Get ISO 9000 Certification? zMany international software development contracts insist: ydevelopment organization to have ISO 9000 certification.

44 Why Get ISO 9000 Certification? zRequires: ya well-documented software production process to be in place. ycontributes to repeatable and higher quality software. zMakes development process: yfocussed, efficient, and cost-effective

45 Why Get ISO 9000 Certification? zPoints out the weakness of an organizations: yrecommends remedial action. zSets the basic framework: yfor development of an optimal process and TQM.

46 How to Get ISO 9000 Certification? zAn organization intending to obtain ISO 9000 certification: yapplies to a ISO 9000 registrar for registration. zISO 9000 registration process consists of several stages.

47 How to Get ISO 9000 Certification? zApplication stage: yApplies to a registrar for registration. zPre-assessment: ythe registrar makes a rough assessment of the organization.

48 How to Get ISO 9000 Certification? zDocument review and adequacy audit: yprocess and quality-related documents. ythe registrar reviews the documents ymakes suggestions for improvements.

49 How to Get ISO 9000 Certification?  Compliance audit: the registrar checks  whether the suggestions made by it during review have been complied.

50 ISO 9000 Certification zAn ISO certified organization ycan use the certificate for corporate advertizements ycannot use the certificate to advertize products. xISO 9000 certifies organization's process xnot any product of the organization. yAn organization using ISO certificate for product advertizements: xrisks withdrawal of the certificate.

51 Summary of ISO 9001 Requirements zManagement responsibility(4.1): yManagement must have an effective quality policy. yThe responsibility and authority of all those whose work affects quality: x must be defined and documented.

52 Summary zISO 9000: ybasic premise: xif a good process is followed xgood products are bound to follow yprovides guidelines for establishing a quality system.