1、Principles of Software Testing for Testers Copyright 2002 Rational Software, all rights reserved 1 软件测试全册配套软件测试全册配套 完整精品课件完整精品课件 Principles of Software Testing for Testers Module 0 About This Course Course Objectives w After completing this course, you will be a more knowledgeable software tester. Y
2、ou will be able to better: Understand and describe the basic concepts of functional (black box) software testing. Identify a number of test styles and techniques and assess their usefulness in your context. Understand the basic application of techniques used to identify useful ideas for tests. Help
3、determine the mission and communicate the status of your testing with the rest of your project team. Characterize a good bug report, peer-review the reports of your colleagues, and improve your own report writing. Understand where key testing concepts apply within the context of the Rational Unified
4、 Process. Intended Audience and Prerequisites w Intended Audience Software testers, quality engineers and other quality- assurance staff who specifically perform software testing activities Software developers who want to understand the goals and tactics of functional testing, as it will probably be
5、 applied to their software Software managers who need to better understand the goals and methods of the testers who will work on their projects w Prerequisite Either six months on-the-job testing experience or significant experience in some other software development role. Course Outline 0 About Thi
6、s Course 1 Software Engineering Practices 2 Core Concepts of Software Testing 3 The RUP Testing Discipline 4 Define Evaluation Mission 5 Test and Evaluate 6 Analyze Test Failure 7 Achieve Acceptable Mission 8 The RUP Workflow As Context Course Materials w Student Workbook These slides with notes Sup
7、plementary papers (e.g. white papers, bibliography.) Note: these materials were initially prepared for Rational by Dr. Cem Kaner and are based jointly on his materials and on Rationals support and educational materials for the Rational Unified Process. Other Sources of Information w Student Workbook
8、 Detailed reference list provided w Rational Developer Network http:/ w Prof. Cem Kaners web site http:/ w Rational Unified Process Principles of Software Testing for Testers Copyright 2002 Rational Software, all rights reserved 8 Principles of Software Testing for Testers Module 1 Software Engineer
9、ing Practices (Some things Testers should know about them) Principles of Software Testing for Testers Copyright 2002 Rational Software, all rights reserved 9 Objectives w Identify some common software development problems. w Identify six software engineering practices for addressing common software
10、development problems. w Discuss how a software engineering process provides supporting context for software engineering practices. Principles of Software Testing for Testers Copyright 2002 Rational Software, all rights reserved 10 Module 1 - Content Outline (Agenda) Software development problems w S
11、ix software engineering practices w Supporting software engineering practices with process Principles of Software Testing for Testers Copyright 2002 Rational Software, all rights reserved 11 Symptoms of Software Development Problems User or business needs not met Requirements churn Modules dont inte
12、grate Hard to maintain Late discovery of flaws Poor quality or poor user experience Poor performance under load No coordinated team effort Build-and-release issues Principles of Software Testing for Testers Copyright 2002 Rational Software, all rights reserved 12 Trace Symptoms to Root Causes Needs
13、not met Requirements churn Modules dont fit Hard to maintain Late discovery Poor quality Poor performance Colliding developers Build-and-release Incorrect requirements Ambiguous communications Brittle architectures Overwhelming complexity Undetected inconsistencies Insufficient testing Subjective as
14、sessment Waterfall development Uncontrolled change Insufficient automation SymptomsRoot Causes Software Engineering Practices Develop Iteratively Manage Requirements Use Component Architectures Model Visually (UML) Continuously Verify Quality Manage Change Continuously Verify Quality Poor quality Un
15、detected inconsistencies Insufficient testing Subjective assessment Principles of Software Testing for Testers Copyright 2002 Rational Software, all rights reserved 13 Module 1 - Content Outline (Agenda) w Software development problems Six software engineering practices w Supporting software enginee
16、ring practices with process Principles of Software Testing for Testers Copyright 2002 Rational Software, all rights reserved 14 Six software engineering practices Develop Iteratively Manage Requirements Use Component Architectures Model Visually (UML) Continuously Verify Quality Manage Change Princi
17、ples of Software Testing for Testers Copyright 2002 Rational Software, all rights reserved 15 Practice 1: Develop Iteratively Develop IterativelyDevelop Iteratively Manage Requirements Use Component Architectures Model Visually (UML) Continuously Verify Quality Manage Change Software Engineering Pra
18、ctices Principles of Software Testing for Testers Copyright 2002 Rational Software, all rights reserved 16 Waterfall Development Characteristics w Delays confirmation of critical risk resolution w Measures progress by assessing work- products that are poor predictors of time-to- completion w Delays
19、and aggregates integration and testing w Precludes early deployment w Frequently results in major unplanned project extensions Design System Test Waterfall Process Requirements Analysis Code harvest test-ideas into catalogs; clarify change request details) Principles of Software Testing for Testers
20、Copyright 2002 Rational Software, all rights reserved 99 Discipline Workflows Guide Iterative Development Example Workflow: Test Example Workflow: Requirements Principles of Software Testing for Testers Copyright 2002 Rational Software, all rights reserved 100 Discipline Workflows Sequence the Workf
21、low Details Example Workflow Detail: Validate Build Stability Principles of Software Testing for Testers Copyright 2002 Rational Software, all rights reserved 101 Module 3 - Review w Presents an iterative testing process w Is Scalable and Customizable w Is designed for Flexibility The RUP Test Disci
22、pline: Principles of Software Testing for Testers Copyright 2002 Rational Software, all rights reserved 102 Principles of Software Testing for Testers Module 4 Define Evaluation Mission Principles of Software Testing for Testers Copyright 2002 Rational Software, all rights reserved 103 Module 4 Agen
23、da w Definition of the workflow: Define Evaluation Mission w Defining the mission of the test group w Defining the goal for test documentation Principles of Software Testing for Testers Copyright 2002 Rational Software, all rights reserved 104 Review: Where Weve Been w In the introductory module we
24、discussed the concepts of quality and test ideas w In the last module, we introduced some of the basic elements in the RUP Test content w Well use those basic RUP elements throughout the remainder of the course to help provide context for what well learn. I / O A A9 9 9 9 A A 9 A 99 A9 9 9 9 9 A A 9
25、 A9 9 Role Activities Artifacts DataBase Test Suite Workflow details Principles of Software Testing for Testers Copyright 2002 Rational Software, all rights reserved 105 Define Evaluation Mission w In this module, we begin with the workflow detail Define Evaluation Mission w The Mission focuses on t
26、he high-level objectives of the test team for the current iteration What things should motivate us to test? Why these things (and not others)? Principles of Software Testing for Testers Copyright 2002 Rational Software, all rights reserved 106 Define Evaluation Mission w This module focuses on the a
27、ctivities that capture the goals of our testing efforts. w We will look at different Missions that test teams use, and consider the implications on the corresponding Test Approach those teams take. w These are the activities that create the Test Plan. Principles of Software Testing for Testers Copyr
28、ight 2002 Rational Software, all rights reserved 107 Module 4 Agenda w Definition of the workflow: Define Evaluation Mission w Defining the mission of the test group w Defining the goal for test documentation Principles of Software Testing for Testers Copyright 2002 Rational Software, all rights res
29、erved 108 Exercise 4.1: Which Group is Better? Found pre- release Function A 100 Function B 0 Function C 0 Function D 0 Function E 0 Total 100 Function A 50 Function B 6 Function C 6 Function D 6 Function E 6 Total 74 Two groups test the same program. The functions are equally important The bugs are
30、 equally significant Testing Group 1 Testing Group 2 Principles of Software Testing for Testers Copyright 2002 Rational Software, all rights reserved 109 Exercise 4.2: Which Group is Better? Found pre- release Found later Total Function A 100 0 100 Function B 0 12 12 Function C 0 12 12 Function D 0
31、12 12 Function E 0 12 12 Total 100 48 148 Function A 50 50 100 Function B 6 6 12 Function C 6 6 12 Function D 6 6 12 Function E 6 6 12 Total 74 74 148 Principles of Software Testing for Testers Copyright 2002 Rational Software, all rights reserved 110 So? Purpose of Testing? w The typical testing gr
32、oup has two key priorities. Find the bugs (preferably in priority order). Assess the condition of the whole product (as a user will see it). w Sometimes, these conflict The mission of assessment is the underlying reason for testing, from managements viewpoint. But if you arent hammering hard on the
33、program, you can miss key risks. Principles of Software Testing for Testers Copyright 2002 Rational Software, all rights reserved 111 Missions of Test Groups Can Vary w Find defects w Maximize bug count w Block premature product releases w Help managers make ship / no-ship decisions w Assess quality
34、 w Minimize technical support costs w Conform to regulations w Minimize safety-related lawsuit risk w Assess conformance to specification w Find safe scenarios for use of the product (find ways to get it to work, in spite of the bugs) w Verify correctness of the product w Assure quality Principles o
35、f Software Testing for Testers Copyright 2002 Rational Software, all rights reserved 112 Exercise 4.3: What Is Your Mission? w Pick a company and a product Probably your own If you dont want to use your current one, pick one everyone knows w Form project teams w Whats the test mission? Principles of
36、 Software Testing for Testers Copyright 2002 Rational Software, all rights reserved 113 A Different Take on Mission: Public vs. Private Bugs w A programmers public bug rate includes all bugs left in the code at check-in. w A programmers private bug rate includes all the bugs that are produced, inclu
37、ding the ones fixed before check-in. w Estimates of private bug rates have ranged from 15 to 150 bugs per 100 statements. w What does this tell us about our task? Principles of Software Testing for Testers Copyright 2002 Rational Software, all rights reserved 114 Defining the Test Approach w The tes
38、t approach (or “testing strategy”) specifies the techniques that will be used to accomplish the test mission. w The test approach also specifies how the techniques will be used. w A good test approach is: Diversified Risk-focused Product-specific Practical Defensible Principles of Software Testing f
39、or Testers Copyright 2002 Rational Software, all rights reserved 115 Heuristics for Evaluating Testing Approach w James Bach collected a series of heuristics for evaluating your test approach. For example, he says: Testing should be optimized to find important problems fast, rather than attempting t
40、o find all problems with equal urgency. w Please note that these are heuristics they wont always the best choice for your context. But in different contexts, youll find different ones very useful. Principles of Software Testing for Testers Copyright 2002 Rational Software, all rights reserved 116 Mo
41、dule 4 Agenda w Definition of the workflow: Define Evaluation Mission w Defining the mission of the test group w Defining the goal for test documentation Principles of Software Testing for Testers Copyright 2002 Rational Software, all rights reserved 117 What Test Documentation Should You Use? w Tes
42、t planning standards and templates Examples Some benefits and costs of using IEEE-829 standard based templates When are these appropriate? w Thinking about your requirements for test documentation Requirements considerations Questions to elicit information about test documentation requirements for y
43、our project Principles of Software Testing for Testers Copyright 2002 Rational Software, all rights reserved 118 IEEE Standard 829 for Software Test Documentation w Test plan w Test-design specification w Test-case specification Test-case specification identifier Test items Input specifications Outp
44、ut specifications Environmental needs Special procedural requirements Intercase dependencies w Test-procedure specification w Test-item transmittal report w Test-log We often see one or more pages per test case. Principles of Software Testing for Testers Copyright 2002 Rational Software, all rights
45、reserved 119 Considerations for IEEE 829 w What is the documentation cost per test case? w What is the maintenance cost of the documentation, per test case? w If software design changes create documentation maintenance costs, how much inertia do we build into our system? How much does extensive test
46、 documentation add to the cost of late improvement of the software? How much should we add? w What inertia is created in favor of invariant regression testing? w Is this incompatible with exploratory testing? Do we always want to discourage exploration? Principles of Software Testing for Testers Cop
47、yright 2002 Rational Software, all rights reserved 120 Requirements for Test Documentation There are many different notions of what a good set of test documentation would include. Before spending a substantial amount of time and resources, its worth asking what documentation should be developed (and
48、 why?) Test documentation is expensive and it takes a long time to produce. If you figure out some of your main requirements first, you might be able to do your work in a way that achieves them. Principles of Software Testing for Testers Copyright 2002 Rational Software, all rights reserved 121 Test
49、 Docs Requirements Questions w Is your test documentation a product or a tool? A product is something that you give to someone else to use. They pay for it. You will probably follow whatever standard they request, subject to their willingness to pay for it. In contrast, if the documentation is merel
50、y an in- house tool, it doesnt have to be any more complete, more organized, or more tidy than the minimum you need to help you meet your objectives. Principles of Software Testing for Testers Copyright 2002 Rational Software, all rights reserved 122 Write a Purpose Statement for Test Documentation
