Supplementary Slides for Software Engineering A Practitioner s Approach

Supplementary Slides for Software Engineering: A Practitioner's Approach, 5/e copyright © 1996, 2001 R. S. Pressman & Associates, Inc. For University Use Only May be reproduced ONLY for student use at the university level when used in conjunction with Software Engineering: A Practitioner's Approach. Any other reproduction or use is expressly prohibited. This presentation, slides, or hardcopy may NOT be used for short courses, industry seminars, or consulting purposes. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R. S. Pressman & Associates, Inc. , copyright © 1996, 2001 1

Chapter 8 Software Quality Assurance These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R. S. Pressman & Associates, Inc. , copyright © 1996, 2001 2

Quality Concepts User satisfaction = compliant product + good quality + delivery within budget and schedule So the quality is essential. quality control: a series of inspections, reviews, tests to ensure that it meet the requirements; includes a feedback loop to the process quality assurance: analysis, auditing and reporting activities, to provide management with the data necessary to be informed about produce quality. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R. S. Pressman & Associates, Inc. , copyright © 1996, 2001 3

Cost of Quality Prevention costs Quality planning Formal technical reviews Test equipment Training Appraisal costs – gain insight into product condition the “first time through” each process In-process and interprocess inspection Equipment calibration and maintenance testing Internal failure costs – a defect in product before shipment Rework Repair Failure mode analysis External failure costs Complaint resolution Product return and replacement Help line support Warranty work These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R. S. Pressman & Associates, Inc. , copyright © 1996, 2001 4

Why SQA Activities Pay Off? cost to find and fix a defect 100 log scale 10 1 60. 00 -100. 00 1. 50 0. 75 1. 00 3. 00 Design testsystem field Req. use code test These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R. S. Pressman & Associates, Inc. , copyright © 1996, 2001 5

Software Quality Assurance SQA Process Definition & Standards Formal Technical Reviews Analysis & Reporting Measurement Test Planning & Review These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R. S. Pressman & Associates, Inc. , copyright © 1996, 2001 6

SQA Activities Prepare an SQA plan for a project. Participates in the development of the project’s software process description. Review software engineering activities to verify compliance with the defined software process. Audits designed software work products to verify compliance with those defined as part of the software process. Ensures that deviations in software work and work products are documented and handled according to a documented procedure. Records any noncompliance and reports to senior management. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R. S. Pressman & Associates, Inc. , copyright © 1996, 2001 7

Reviews & Inspections. . . there is no particular reason why your friend and colleague cannot also be your sternest critic. Jerry Weinberg These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R. S. Pressman & Associates, Inc. , copyright © 1996, 2001 8

What Are Reviews? a meeting conducted by technical people for technical people a technical assessment of a work product created during the software engineering process a software quality assurance mechanism a training ground These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R. S. Pressman & Associates, Inc. , copyright © 1996, 2001 9

What Reviews Are Not! They are not: a project budget summary a scheduling assessment an overall progress report a mechanism for reprisal or political intrigue!! These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R. S. Pressman & Associates, Inc. , copyright © 1996, 2001 10

Formal Technical Reviews (FTR) To uncover errors in fuction, logic, or implementation for any representation of the software To verify that the software meets its requirements To ensure that the software had been represented according to predefined standards To achieve software that is developed in a uniform manner To make projects more manageable These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R. S. Pressman & Associates, Inc. , copyright © 1996, 2001 11

The Players of FTR Meeting review leader standards bearer (SQA) producer maintenance oracle reviewer recorder user rep These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R. S. Pressman & Associates, Inc. , copyright © 1996, 2001 12

Conducting the Review 1. be prepared—evaluate product before the review 2. review the product, not the producer 3. keep your tone mild, ask questions instead of making accusations 4. stick to the review agenda 5. raise issues, don't resolve them 6. avoid discussions of style—stick to technical correctness 7. schedule reviews as project tasks 8. record and report all review results These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R. S. Pressman & Associates, Inc. , copyright © 1996, 2001 13

Review Options Matrix IPR * trained leader agenda established reviewers prepare in advance producer presents product “reader” presents product recorder takes notes checklists used to find errors categorized as found issues list created team must sign-off on result WT IN no maybe no no yes yes no no yes yes yes RRR yes yes no no yes maybe * IPR—informal peer review WT—Walkthrough IN—Inspection RRR—round robin review These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R. S. Pressman & Associates, Inc. , copyright © 1996, 2001 14

Metrics Derived from Reviews inspection time per page of documentation inspection time per KLOC or FP inspection effort per KLOC or FP errors uncovered per reviewer hour errors uncovered per preparation hour errors uncovered per SE task (e. g. , design) number of minor errors (e. g. , typos) number of major errors (e. g. , nonconformance to req. ) number of errors found during preparation These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R. S. Pressman & Associates, Inc. , copyright © 1996, 2001 15

Statistical SQA Product & Process • collect information on all defects • find the causes of the defects • move to provide fixes for the process measurement. . . an understanding of how to improve quality. . . These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R. S. Pressman & Associates, Inc. , copyright © 1996, 2001 16

The ISO 9001 Standard A quality assurance standard that applies to software engineering. It contains 20 requirements that must be present for an effective quality assurance system Management responsibility Quality system Contract review Design control Document and data control Product identification and traceability Process control Inspection and testing. . . After adopting the standards, a country typically permits only ISO registered companies to supply services to government agencies and public utilities. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are provided with permission by R. S. Pressman & Associates, Inc. , copyright © 1996, 2001 17