Guideline: TPA - Input And Starting Conditions

To perform a test point analysis, one must have a functional design. The functional design must include detailed process descriptions and a logical data model, preferably including a CRUD matrix. Moreover a function point count must have been executed according to IFPUG. These function point methods can be used as input for TPA. It is important to use only one of these function point methods when determining the skill factor, not multiple methods combined. In a function point count, the number of gross function points is taken as the starting point. Which function point method is used is not important when determining the test points. It will, however, have an impact on the skill factor.

The following modifications must be made to the function point count for TPA:

The function points of the (logical) data collections distinguished in the function point count must be allocated to the function(s) that handle(s) the input of the relevant (logical) collection.
The function points of the interface data collections distinguished in the function point count must be allocated to the function (or possibly functions) that use(s) the relevant interface data collection.
For FPA functions in the clone class, the number of function points that applies to the original FPA function is used. A clone is an FPA function that has already been specifi ed and/or realised in another, or the same, user function in the project.
For FPA functions in the dummy class, the number of function points is determined if possible. Else this FPA function is given the qualification average complexity and the corresponding number of function points. A dummy is an FPA function if the functionality does not have to be specified and/or realised, but is already available because it was specified/realised outside the project.

Estimating guideline for counting function points

If no function point count is available and you wish to make one (for TPA), the following guideline can be used to determine the time required to count the function points: Determine the number of TOSMs using one of the methods described Estimation Based On Test Object Size and divide it by 400. The outcome represents an estimate of the number of days necessary to count the function points. Note: as a rule, 350 to 400 function points can be counted in a day.

Calculation example: Number of function points (FP_f)

An information system has two user functions and one internal logical data collection:

Registration (11 function points), with as underlying FPA functions:

· Entry: 3 function points

· Editing: 4 function points

· Deleting: 4 function points

Processing (12 function points), with as underlying FPA functions:

· Overview 1: 5 function points

· Overview 2: 7 function points

The internal logical data collection ‘data’ has 7 function points and is allocated to the entry function in the context of test point analysis.

FP_f Registration: 18 function points

FP_f Processing: 12 function points

(FP_f = function points per function)