Test Levels & Techniques

Static Testing Static testing refers to testing that takes place without Execution - examining and reviewing it. Dynamic Testing Dynamic testing is what you would normally think of testing - executing and using the software.

Dynamic Testing Techniques used are determined by the type of testing that must be conducted Functional Structural

Functional Testing Structure of the program is not considered. Test cases are decided based on the requirements or specification of the program or module Hence it is often called as “Black Box Testing”.

Structural Testing Concerned with testing ,the implementation of the program. Focus on the internal structure of the program. The intent of structural testing is not to exercise all the different input or output condition but to exercise the different programming structures and data structures in the program.

Phases of software testing: Unit Testing Integration/Build Testing Validation/Functional Testing System Testing Acceptance Testing Testing Levels

Unit Testing Test each module individually. Follows a white box testing (Logic of the program)

Integration testing Integrate two or more module.i.e. communicate between the modules. Follow a white box testing (Testing the code)

Integration Testing - Overview

System Testing Confirms that the system as a whole delivers the functionality originally required. Follows the black box testing.

System Testing - Goals Incorrect or missing feature Performance errors Security errors User interface errors Configuration and compatibility Compliance to required standards

System Testing - Overview System Tests: Define test procedures and instructions Review test plans Execute test plans Record results

System Testing - Strategy Developing System Tests stress tests security tests recovery tests performance tests

User Acceptance Testing (UAT) Building the confidence of the client and users is the role of the acceptance test phase. It is depend on the business scenario. Those functions required by the customer to demonstrate sufficient functionality and reliability to warrant acceptance.

V-Model Unit Integration System UAT LLD HLD SRS Business scenario

Testing Techniques White Box Black Box Incremental Thread

White Box Testing - Internal Purpose of Unit Tests: Test all loops Test Basis paths Test conditional statements Test data structures * develop unit tests after the design portion of the Build Definition Spec. is completed.

White Box Testing Techniques Statement coverage – execute all statements at least once. Decision coverage - execute each decision direction at least once. Condition coverage – execute each decision with all possible outcomes at least once

White Box Testing Techniques Loop Testing: Simple Loops Nested Loops Concatenated Loops Unstructured Loops

Black Box Testing - External Black Box Testing verifies that the requirements have been met. How is functional validity tested How is system behavior and performance tested. What classes of input will make good test cases? Is the system particularly sensitive to certain input values? How are the boundaries of a data class isolated? What data rates and data volume can the system tolerate? What effect will specific combinations of data have on system operation?

Black Box Testing - External Black Box Tests look for: incorrect or missing functions interface errors errors in external database access behavior or performance errors

Black Box Testing Techniques * Equivalence Partitioning * Boundary Analysis * Error Guessing

Equivalence Partitioning A subset of data that is representative of a larger class For example, a program which edits credit limits within a given range ($10,000 - $15,000 would have 3 equivalence classes: Less than $10,000 (invalid) Between $10,000 and $15,000 (valid) Greater than $15,000 (invalid)

Boundary Analysis A technique that consists of developing test cases and data that focus on the input and output boundaries of a given function

Boundary Analysis continued... In the same credit limit example, boundary analysis would test: Low boundary plus or minus one ($9,999 and $10,001) On the boundary ($10,000 and $15,000) Upper boundary plus or minus one ($14,999 and $15,001)

Error Guessing Based on the theory that test cases can be developed based on experience of the Test Engineer For example, in an example where one of the inputs is the date, a test engineer might try February 29,2000 or 9/9/99

Incremental Testing A disciplined method of testing the interfaces between unit-tested programs as well as between system components Incremental Testing Types - Top-down - Bottom-up

Top-Down Begins testing from the top of the module hierarchy and works down to the bottom using interim stubs to simulate lower interfacing modules or programs

Bottom-Up Begins testing from the bottom of the hierarchy and works up to the top Bottom-up testing requires the development of driver modules which provide the test input, call the module or program being testing, and display test output

A technique, often used during early integration testing Demonstrates key functional capabilities by testing a string of units that accomplish a specific function in the application Thread Testing

Illustrates various techniques used throughout the test stages

Test Levels & Techniques

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Test Levels & Techniques