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1 QUALITY ASSURANCE - PROCESS QUALITY METRICS PREREQUISITES Top - PDF document

SOFTWARE ENGINEERING SOFTWARE QUALITY - SOFTWARE QUALITY QUALITY COMPONENTS Today we talk about software process quality and Objective quality component: properties that can certification be measured or approximated objectively


  1. SOFTWARE ENGINEERING SOFTWARE QUALITY - SOFTWARE QUALITY QUALITY COMPONENTS • Today we talk about software process quality and • Objective quality component: properties that can certification be measured or approximated objectively • Subjective quality component: customer satisfaction (”What does the product feel like?”) • Other: features which can not be (even subjectively) evaluated at the time. This is related with future events which can not be predicted - unexpected circumstances, changes, etc. 24.3.2004 Software Engineering 2004 1 24.3.2004 Software Engineering 2004 2 Jyrki Nummenmaa Jyrki Nummenmaa THE QUALITY SYSTEM THE QUALITY SYSTEM (cont’d) • Quality control - controlling the way things are • The quality system of a company is simply the way done the company works and it covers all areas of activity. • Quality assurance - making sure quality is achieved • Quality policy • Therefore, a quality system always exists. It may be documented or not. • Quality planning • Quality improvement • However, in the long run in a big company it makes a major difference, if the management • These terms come from the standard ISO 8402 takes quality seriously and knowingly emphasizes it in all activities. 24.3.2004 Software Engineering 2004 3 24.3.2004 Software Engineering 2004 4 Jyrki Nummenmaa Jyrki Nummenmaa QUALITY CONTROL QUALITY ASSURANCE • Controlling the software development process • Improving software quality by monitoring the products (software) and process • Standards for the development process, e.g. - well-defined phases - checklists • Ensuring full compliance with the standards for - reviews: what and when products and process - organisational standards • Visibility and bookkeeping of the development • Ensuring that any inadequacies in the product and process process (and standards) are brought to • Standards for software code and documentation, e.g. management’s attention. - naming and style - document skeletons and formats - different kinds of review and feedback forms 24.3.2004 Software Engineering 2004 5 24.3.2004 Software Engineering 2004 6 Jyrki Nummenmaa Jyrki Nummenmaa 1

  2. QUALITY ASSURANCE - PROCESS QUALITY METRICS PREREQUISITES • Top management commitment • Actual vs. estimated time and cost • The quality assurance organisation must be • Number of faults detected independent from the development organisation. • Phase of the project when faults were found • The quality assurance organisation must be properly staffed. • Productivity (e.g. lines of code / man-month) • The quality assurance organisation must co- • Quality expenses (e.g. repairs required after operate properly with the development delivery) organisation. Quality must be seen as a common goal. 24.3.2004 Software Engineering 2004 7 24.3.2004 Software Engineering 2004 8 Jyrki Nummenmaa Jyrki Nummenmaa A GENERAL SCHEME FOR QUALITY REVIEW TYPES REVIEWS • Design or program inspections/audits. These are • Select the review team. commonly driven by a checklist of possible errors. • Arrange the place and time. • Management reviews. These are intended to provide information for the management about the • Distributed the documents. overall progress of the software project. • Hold the review. • Quality reviews. The work of an individual or a team is reviewed by a panel made up of project • Note the actions and complete the review forms. members and technical management. 24.3.2004 Software Engineering 2004 9 24.3.2004 Software Engineering 2004 10 Jyrki Nummenmaa Jyrki Nummenmaa POSSIBLE ACTIONS FOR INSPECTIONS / AUDIT SESSIONS FINDINGS IN REVIEWS • No action. Some kind of an anomaly was found, • The ”Fagan method” - named after an IBM but it was not cost-effective to fix it. employee who pioneered the technique • All types of defects are noted - not just logic or function errors. • Refer for repair. The team or individual in charge of the product has to correct the fault. • Inspections can be carried out by collagues at all levels except the very top. • Inspections are carried out using a predefined set • Reconsider the overall design. It may be more of steps. reasonable to fix other components of the system to solve the problem which was found. • Inspection meetings do not last for more than two hours. • The inspection is lead by a moderator who has a specific trainging in the technique. 24.3.2004 Software Engineering 2004 11 24.3.2004 Software Engineering 2004 12 Jyrki Nummenmaa Jyrki Nummenmaa 2

  3. INSPECTIONS / AUDIT SESSIONS A CHECKLIST FOR (continued) REVIEW EVALUATIONS • The other participants have defined roles. For • Is material complete (and does it meet the example, one person will act as a recorder and standards)? note all defects found and another will act as a • Was material distributed on time? reader who takes the other participants through • Are applicable standards referenced and available? the document under inspection. • Were attendees prepared to contributed? • Checklists are used to assist the fault-finding • Did evaluation start on time? process. • Were number of defects identified? • Material should be inspected at an optimal rate of • Was review conducted per standard protocols? about 100 lines per hour. • Were entrance criteria met? • Statistics are maintained so that the effectiveness of the inspection process can be monitored. • Were exit criteria met? 24.3.2004 Software Engineering 2004 13 24.3.2004 Software Engineering 2004 14 Jyrki Nummenmaa Jyrki Nummenmaa A CHECKLIST FOR SOFTWARE QUALITY CIRCLES REVIEW EVALUATIONS (cont’d) • Are all issues scheduled for resolution? • A Japanese practice. • Are interface issues coordinated? • Is disposition of all defects complete? • A quality circle is a group of four to ten volunteers working in the same area who meet for, say, an • Were HCI, testing, maintenance, and tools hour a week to identify, analyse and solve their considered? work-related problems. • Were quality attributes reported? • Has trace of defects been initiated? • One of the group is a group leader and one (maybe from outside) is a facilitator giving advice. • Training is required, and so is full support from the management. 24.3.2004 Software Engineering 2004 15 24.3.2004 Software Engineering 2004 16 Jyrki Nummenmaa Jyrki Nummenmaa PROBLEM SOLVING BY ISO 9000 SOFTWARE QUALITY CIRCLES • Identify a list or problems and choose one. • Series of standards for general use in different fields of industry. • Clarify the problem. • ISO 9001 is for companies with product • Identify and evaluate the causes. development and production. • Identify and evaluate the solutions. • Separate certification organisations give • Decide on the solution. certification for companies which fulfill the • Develop an implementation plan. requirements of the standards. • Present the plan to the management. • Implement the plan. • Monitor the plan. • Consider wider apllicability of solution. • Restart from choosing another problem. 24.3.2004 Software Engineering 2004 17 24.3.2004 Software Engineering 2004 18 Jyrki Nummenmaa Jyrki Nummenmaa 3

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