The formula in Total Number Of Test Points results in the total number of test points. This is the measure for the scope of the primary test activities. These primary test points are multiplied by the skill factor and the environment factor to obtain the primary test hours. This represents the time that is necessary to execute the test activities for the Preparation, Specification, Execution and Completion phases of the TMap model.

SKILL FACTOR

The skill factor indicates how many hours of testing are required per test point. The higher skill factor, the greater the number of hours of testing.

The productivity with which the test object is tested on the basis of the test strategy depends primarily on the knowledge and skills of those executing the tests. It is also relevant to know if people are testing part-time or full-time. Testing users that are deployed for test work only part of the workday, have a lot of switch moments between their day-to-day work and the test work, which often results in reduced productivity.

In practice, the following basic figures are used per test point:

• 1-2 hours for a tester, depending on knowledge and skills
• 2-4 hours for a user, depending on experience.

The skill factor naturally varies per organisation and within that even per department/person. A factor can be obtained by analysing completed test projects. To make such an analysis, one must have access to experience figures for the test projects already realised.

Calculation example 1 - Skill factor

For the relevant organization, a skill factor of 1.2 applies. S = 1.2

ENVIRONMENT FACTOR

The number of required test hours per test point is influenced not only by the skill factor, but by the environment factor as well. A number of environment variables are used to calculate this. The environment variables are described below, including the associated weights. Again, only one of the available values may be selected. If too little information is available to classify a certain variable, it must be given the nominal value.

Test tools

The test tools factor involves the level to which the primary text activities are supported by automated test tools. Test tools can contribute to executing part of the test activities automatically and therefore faster. Their availability does not guarantee that, however - it is about their effective use.

Weight:

• 1 - the test uses support tools for test specification, and a tool is used for record & playback
• 2 - test execution uses support tools for test specification, or a tool with record & playback options is used
• 4 - no test tools are available.

Previous test

For this factor the quality of the test executed earlier is important. When estimating an acceptance test this is the system test, when estimating a system test, the development test. The quality of the previous test is a co-determinant for the quantity of functionality that may be tested at a more limited level as well as for the lead time of the test execution. When the previous test is of a higher quality, fewer progress-hindering defects will occur.

Weight:

• 2 - a test plan is available for the previous test, and the test team also has insight into the concrete test cases and test results (test coverage)
• 4 - a test plan is available for the previous test
• 8 - no test plan is available for the previous test.

Test basis

The test basis is awarded a factor representing the quality of the (system) documentation on which the test for execution must be based. The quality of the test basis has an impact in particular on the required time for the Preparation and Specification phases.

Weight:

• 3 - standards and templates are used to create the system documentation. The documentation is also subject to inspections
• 6 - standards and templates are used to create the documentation
• 12 - no standards and templates are used to create the system documentation.

Development environment

The environment in which the information system is realised. Of particular interest here is to what extent the development environment prevents errors and/or enforces certain things. If certain errors can no longer be made, clearly they do not require testing.

Weight:

• 2 - the development environment contains a large number of facilities that prevent errors being made for example by executing semantic and syntactic checks and by taking over the parameters
• 4 - the development environment contains a limited number of facilities that prevent errors being made for example by executing a syntactic check and by taking over the parameters
• 8 - the development environment contains no facilities that prevent errors being made.

Test environment

The extent to which the physical test environment in which the test is executed has proven itself. If an often used test environment is used, fewer disturbances and defects will occur during the Execution phase.

Weight

• 1 - the environment has already been used several times to execute a test
• 2 - a new environment has been set up for the test in question, the organisation has ample experience with similar environments
• 4 - a new environment has been set up for the test in question that can be characterised as experimental for the organisation.

Testware

The level to which existing testware can be used during the test to be executed. The availability of effective testware has a particular impact on the time required for the Specifi cation phase.

Weight:

• 1 - a usable general central starting situation (tables etc.) is available, as well as specified test cases for the test to be executed
• 2 - a usable general central starting situation (tables etc) is available
• 4 - no usable testware is available.

Calculation method

The environment factor (E) is determined by establishing the sum of the values of the environment variables (test tools, previous test, test basis, development environment, test environment, and testware) and dividing it by 21 (the nominal value). The environment factor E can be established for the total system once, but also per sub-system if necessary.

Calculation example 2 - Environment factor (E)

The various environment variables were given the score below:

E = 20/21 = 0.95

FORMULA FOR PRIMARY TEST HOURS

The number of primary test hours is obtained by multiplying the number of test points by the skill and environment factors:

PT = TP * S * E

PT = the total number of primary test hours
TP = the number of test points of the total system
S = skill factor
E = environment factor

Calculation example 3 - Calculation of primary test hours (PT)

PT = 48 * 1.2 * 0.95 = 54.72 (55 hours)