when-to-write-a-test.md

When to write a test

To decide whether a test should be written, a risk analysis should be done according to the decision table below:

Impact	Very large	5	10	15	20	25
	Large	4	8	12	16	20
	Medium	3	6	9	12	15
	Small	2	4	6	8	10
	Very small	1	2	3	4	5
		Very unlikely	Unlikely	Plausible	Likely	Very likely
		Chance

Explanation

• 1 - 2: No test needed;
• 3 - 12: A test must be written, unless this is not justified due to cost or time involved and thus the business interest;
• 15 - 25: A test must be written.