4.3. Coverage policies
To achieve the quality targets while also achieving the cost targets, the test material to be covered needs to be considered in order to enable efficient testing.
In this topic, you will consider on what will be covered in the tests.
This is arguably an element of “4.1. Test policies“, as these policies apply to all testing, but where these policies differ from the points considered in “4.1. Test policies” is that it is easiest to consider them after considering on 4.2. Position of test phases“. We have therefore designated a separate chapter for these considerations.
Overview of points to be considered
If testing is conducted with a high rate of coverage (a large number of points* are covered), fewer points will be left unconfirmed and quality will be confirmed for a wider scope.
The disadvantage is that this means there will be more test cases, which tends to result in testing taking longer or costing more.
The purpose of considering on the points to be covered by tests at the overall test planning stage is to prevent misunderstandings between stakeholders about the quality to be confirmed by the tests and the money and time that is required for those confirmations.
*For the purposes of this chapter, points covered by tests are items, requirements and similar that will be verified in testing.
Refer to project materials such as the requirement definitions and the “Count targets” column in” the test perspective catalog” (reference material).
- Examples of points to be covered
- Features, performance requirements, etc.
- Screens, types of database update processes, etc.
- Program structure
- Program statements, branches, etc.
- Anticipated user activity patterns
- Screen operation patterns, etc.
- Checklists and perspectives that need to be confirmed for the project or for organizational purposes
- Coverage indicated in “the test perspectives catalog” in “Test Type & Viewpoint Catalog” (reference material), points to be covered in checklists for detecting anticipated bugs and bugs that have occurred in similar projects in the past, etc.
Relationship between this topic and other topics in the overall test plann
This topic is mainly related to the following topics as shown below.
Relationship between this topic and other topics
- １.Confirm the points that were investigated and considered in “4.1.Test policies“, including quality targets to be achieved.
- ２.The quality objectives and risks identified in the previous section and related coverages are organized according to the testing policy. In some cases, the covers may be combined with each other.
- It is best to consider these for each test phase or test type.
- The level of detail that needs to be covered may vary depending on the purpose of each test.
- For example, if multiple types of values can be entered for a particular item, you will need to consider whether to test every type or whether to select one valid value type and one invalid value type and test only those two types.
- ３.Check that this coverage is consistent with the considerations you made in “4.1. Test policies“.
- If it is not consistent, this will need to be addressed by changing the test policies to alter the budget or time assigned to testing or by decreasing the points covered by testing.
In either case, the scope needs to be sufficient to meet the quality targets and the stakeholders must all be on the same page about it.
- ４.Confirm the revised conditions about the points to be covered.
- For example, if the points to be covered are determined in terms of requirements, coverage will be affected by any changes in the requirements. Prerequisites therefore need to be established for revisions.
- The target coverage rate can be less than 100% if there are any areas that are within the scope of testing but have a low risk of bugs.
- Consider on a test method based on the points that will be covered and the target coverage rate.
- For example, if the points to be covered are statuses, consider conducting status transition tests.