Book Image

Software Test Design

By : Simon Amey
Book Image

Software Test Design

By: Simon Amey

Overview of this book

Software Test Design details best practices for testing software applications and writing comprehensive test plans. Written by an expert with over twenty years of experience in the high-tech industry, this guide will provide you with training and practical examples to improve your testing skills. Thorough testing requires a thorough understanding of the functionality under test, informed by exploratory testing and described by a detailed functional specification. This book is divided into three sections, the first of which will describe how best to complete those tasks to start testing from a solid foundation. Armed with the feature specification, functional testing verifies the visible behavior of features by identifying equivalence partitions, boundary values, and other key test conditions. This section explores techniques such as black- and white-box testing, trying error cases, finding security weaknesses, improving the user experience, and how to maintain your product in the long term. The final section describes how best to test the limits of your application. How does it behave under failure conditions and can it recover? What is the maximum load it can sustain? And how does it respond when overloaded? By the end of this book, you will know how to write detailed test plans to improve the quality of your software applications.
Table of Contents (21 chapters)
Part 1 – Preparing to Test
Part 2 – Functional Testing
Part 3 – Non-Functional Testing
Appendix – Example Feature Specification

Defect hiding

Load testing uncovers some of the toughest bugs to find and fix, especially because one issue can obscure others. On the user interface, in contrast, you can see multiple problems simultaneously, but that’s not always the case with loading. If your application crashes after 3 days of loading due to a memory leak, that will hide the fact that it also crashes after 4 days due to an ID rolling over. You will need to test, investigate, fix, and release a new build for the first issue before you can start to look for subsequent problems.

Because of this, loading results are often on a measured scale rather than passing or failing. You can measure your Mean Time Between Failures (MTBF) while running under load, which averages the time before a malfunction for any reason. You can then convert the MTBF into a pass or fail result – to pass, load testing must run successfully for more than a week, for instance.

Real-world example – Checking the crash...