A fix defining at least one unique change to at least a portion of a computer program can be identified. The fix can be applied to the computer program to generate a test version of the computer program As each of the unique changes is applied, program code unites in the computer program changed can be identified. A number of test cases available to test the program code units changed can be determined by matching each of the program code units changed to corresponding data entries. A test readiness index indicating a readiness of the fix to be tested can be generated. The test readiness index can be based on a number of unique changes to the computer program defined by the fix and a number of test cases available to test the unique changes to the computer program defined by the fix. The test readiness index can be output.