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

Understanding the test activities

When performing system testing, there are four main activities. Each of them interacts and feeds into all the others, as shown in the following diagram:

Figure 1.7 – The main test activities and their interactions

Figure 1.7 – The main test activities and their interactions

Test design includes all the information gathering and preparation activities performed before you begin testing, excluding exploratory testing, which is significant enough to have its own category. Test design means reviewing all the available information for this feature to plan your testing. The written materials you base your testing on are collectively known as the test basis and may include documents such as the following:

  • User stories
  • Specifications
  • User interface designs
  • Technical design documents
  • Competitive research

These documents help show the new behavior, although you will need to add extra details yourself. This will be described further in Chapter 2, Writing Great Feature Specifications. Even the written information is insufficient and needs to be augmented with practical experience of the feature, which comes from exploratory testing.

Exploratory testing is an oddity. Technically, it is part of the test design since its main focus is gathering information to inform future testing. However, it occurs relatively late in the process, when there is code ready to be tested, and unlike the rest of the test design, it involves testing and potentially finding bugs. Because of this dual role, it gets its own category.

With the information from the test basis and exploratory testing, you can document the feature specification and the test plan based on it. This should exhaustively describe a feature’s behavior, covering all possible eventualities.

Important note

The detailed testing then methodically runs the entire test plan. That may involve manual testing or writing and running automated tests. This book does not describe how to run your tests; other titles in the Packt library have excellent descriptions of those possibilities. This book focuses on the test design to show what tests you should run.

The final step is further documentation, this time of your test results. This includes all the bugs you need to raise and describing the tests that have passed.

These are the main activities a tester performs. There are other important jobs around planning, including allocating personnel and resources, estimating timescales, and scheduling work. Those are not shown in the preceding diagram and are out of scope for this book because they primarily require skills in project management. They must also be in place to run a successful test project, but here, I am concentrating on the details of what testing is required so that you can plan these activities as accurately as possible.

Each of those four test activities feeds back into the others. Designing tests is necessary before they can be documented and run, but the test results also show where more tests are needed. Some test planning is essential for exploratory testing, but exploratory testing also shows which tests need to be designed and executed for complete coverage. Documenting the feature specification should start before exploratory testing so that you know what changes to expect. However, it can only be finished once exploratory testing is complete, to answer any questions that arise.

Where in those interrelated activities should we begin? As you can see from the title of this chapter, I believe exploratory testing is a good place to start. There will be specifications and planning before that, but exploratory testing is the first test task you can finish. With that in place, you can aim to complete the specification, the test plan design, and the detailed testing itself. Because of that unique attribute, we will start with it here.

For each part of the feature, testing should move between those different test activities and feed back to the other design tasks of writing specifications, implementing, and developer testing described previously. How do these tasks fit together, and how do they progress toward the goal of releasing a well-specified and tested feature? The following section describes the ordered flow of activities and their progression.