Test environment is essential for testing team in order for tests to be accurate. Usually, software works well on developers machines. However the same software fails soon after installing it on customer environment. Having a dedicated test environment helps a lot in finding such kind of issues and fixing them before delivering software to the customer.
Test environment should match customer environment. This includes hardware and software in addition to the operating system in use. In addition, test environment should not have any development software and access to this environment should be granted to testing team members only.
Designing test environment is done within Test Analysis and Design phase of the fundamental software testing process. This includes designing the test environment setup and identifying any required infrastructure and tools. In Test Implementation and Execution phase, the test environment is set up and tests are run. After testing is run and in Test Closure Activities phase, the test environment is finalized and archived for later use.
All the best..
* Reference: ISTQB CTFL Syllabus 2011