1. CPIS 357 Software Quality & Testing
I.Rehab Bahaaddin Ashary
Faculty of Computing and Information Technology
Information Systems Department
Fall 2010

2. Lecture Objectives Chapter 1 :Basic Concepts and Preliminaries
Central Issue in Testing
Testing Activities
Test Levels
Sources of Information for Test Case Selection
White- Box and Black – Box Testing
Test Planning and Design
Monitoring and Measuring Test Execution
Test Tools and Automation
Test Team Organization and Management

3. Central Issue in Testing
Figure 1: A subset of the input domain exercising a subset of the program behavior
Divide the input domain D into D1 and D2
Select a subset D1 of D to test program P
It is possible that D1 exercise only a part P1 of P
Selection of the subset of the input domain must be done in a systematic and careful manner so that the deduction is as accurate and complete as possible. For example. The idea of coverage is considered while selecting the test case.

4. Figure 2: Different activities in process testing
Testing Activities
Figure 2: Different activities in process testing
Identify the objective to be tested. (Purpose designing one or more test case)
Select inputs.(Requirements specification, source code)
Compute the expected outcome.(High Level understanding both objective and specification)
Set up the execution environment of the program. (Local/Remote)
Execute the program.(Different location at different time)
Analyze the test results.(Pass/Fail/Inconclusive)

5. Figure 3: Development and testing phases in the V model
Test Levels
Unit testing
Individual program units, such as procedure, methods, Function and Classes in isolation
Integration testing
Modules are assembled to construct larger subsystem and tested by software developer and test engineer
System testing
Includes wide spectrum of testing such as functionality, Security, Stability, Performance, reliability and load
Acceptance testing
Customer’s expectations from the system
Two types of acceptance testing
UAT: System satisfies the contractual acceptance criteria
BAT: System will eventually
Measure the quality of the product rather than searching for the defect.
Figure 3: Development and testing phases in the V model

6. Figure 4: Regression testing at different software testing levels
Test Levels
Figure 4: Regression testing at different software testing levels
New test cases are not designed
Test are selected, prioritized and executed
To ensure that nothing is broken in the new version of the software

7. Source of Information for Test Case Selection
Requirement and Functional Specifications
Capturing user needs.
Informal or formal manner
Examples: plaintext, flowchart, figures, equations, use case, entity relationship diagram or class diagram
Source Code
Internal behavior of the system.
By software engineer (for the design details) and programmer add more details Example: Sort Function
Input and Output Domain
Example: factorial (0) =1; factorial (1) =1 ;
factorial (n) =n* factorial (n-1)
Operational Profile
Is a quantitative characterization of how the system will be used and guide test engineers in selecting test case input.
Fault Model
Error Guessing
Fault Seeding (Fault Injection)
Mutation Analysis (Fault Simulation)

8. White-box and Black-box Testing
White Box Testing
( Structural Test)
Black Box Testing
(Functional Test)
Examines source code with focus on:
Control Flow
Data Flow
Control flow refers to flow of control
from one instruction to another.
Data flow refers to propagation of
values from one variable or constant
to another variable.
It is applied to individual units of a program.
Software developers perform structural testing on the individual program units they write
Examines the program that is accessible from outside
Applies the input to a program and
observe the externally visible outcome.
It is applied to both an entire program as well as to individual program units.
It is performed at the external interface level of a system.
It is conducted by a separate software quality assurance group.

9. Test Planning and Design
The purpose is to get ready and organized for test execution.
A test plan provides a:
Framework
A set of ideas, facts or circumstances within which the tests
will be conducted.
Scope
The test activities and the outline of the domain.
Details of resource needed
Effort required
Schedule of activities
Budget
During the test design phase the system requirements are critically studied, system features to be tested and the objective and the detailed behavior of test cases are defined.
Test objectives are identified from different sources.
Each test case is designed as a combination of modular test components called test steps.
Test steps are combined together to create more complex tests.

10. Monitoring and Measuring Test Execution
Metrics for monitoring test execution (concern on test).
Metrics for monitoring defects (concern on the result from the test).
Needed to be tracked and analyzed in a periodic basic (daily or weekly).
Metrics is meaningful if enable management to make decision making which reduce delay, improve quality and lower the cost.
The evaluation done through the following:
Evaluate the effectiveness, Evaluate productivity, Evaluate the quality,
Evaluate the product.
Test case effectiveness metrics
Measure the “defect revealing ability” of the test suite
Use the metric to improve the test design process
Test-effort effectiveness metrics
Number of defects found by the customers that were not found by the test engineers
After product Developed.

11. Test Tools and Automation
strengths
Prerequisites List
Increased productivity of the testers.
Better coverage of regression testing.
Reduced durations of the testing phases.
Reduced cost of software maintenance.
Increased effectiveness of test cases.
The test cases to be automated are well defined.
Test tools and an infrastructure are in place.
The test automation professionals have prior successful experience in automation.
Adequate budget have been allocation for the procurement of software tools.
Weaknesses
Long learning Curves.
High time and cost for test preparation.
Test tool limitation.

12. Figure 5: Structure of test groups
Test Team Organization and Management
Figure 5: Structure of test groups
Unit Testing  Programmer
System Integration  Test engineer
System test group  must be separated from development group and they put the plan for the UAT, BAT
Acceptance  Client special group (SW quality assurance engineer, business associate, customer support engineer)
Hiring and retaining test engineers is a challenging task.
Interview is the primary mechanism for evaluating applicants.