The test plan contains, among other things, a summary of the information of which the test basis consists, as well as the test strategy. However, if it appears that the agreed (documented) test basis is partly or entirely lacking, it may be that the testing has to be carried out on the basis of different (non-documented) information. In that case, not all the test design techniques are suitable. Some test design techniques that are often suitable in such a situation are:

• The data combination test (DCoT), also known as the “classification tree method” (CTM)
• Error guessing
• Exploratory testing
• Boundary value analysis
• Checklist.

For notes on these test design techniques and the use of them, refer to the guideline Test Design Techniques below.