Use Case Point Counts in the Function Point WORKBENCH™
Use Case Points are a software sizing measure that can be used to quantify
software specifications expressed as Use Cases. Use Case
specifications are used within various object oriented software development
methodologies including the Rational Unified Process from IBM and Process
Mentor from Object Consulting.
Although the various methods for determining Use Case Points usually follow the same
high level process, the details of how each method assigns weights
to individual Use Cases typically vary. The Use Case Point measure
described on this page incorporates weights as defined by Gustuv Karner in
1993. This approach is used in a range of software development and
estimating tools and procedures.
As Use Case Points are a fairly new software sizing measure, there is not
yet a substantial body of knowledge available to enable their effectiveness
for tasks such as project estimating or development benchmarking to be
properly assessed. For this reason CHARISMATEK has chosen to address
Use Case Points as an adjunct to the Function Point WORKBENCH™ via the Function Point
WORKBENCH™ - Publisher tool, as opposed to incorporating them into the
Function Point WORKBENCH™itself.
On this page we outline a procedure whereby any Function Point WORKBENCH™
users who wish to use Use Case Points to size their new development or
enhancement projects can do so. The procedure utilises a number of
report templates developed for use with the Function Point WORKBENCH™ -
Publisher tool.
If you wish to modify the Publisher Use Case Point report templates to
address your own software sizing measures, please feel free to do so.
Alternatively, please contact CHARISMATEK and we will be happy to advise you
on what would be required in order to use the WORKBENCH and Publisher to
size and report using your own software sizing measures.
Please note that the Use Case Point report templates
can be downloaded for free from the
Function Point WORKBENCH™ -
Publisher page.
Performing a Use Case Point Count
In the Function Point WORKBENCH™, Use Case Point Counts are performed
using the same approach that is used for Function Point Counts. A
hierarchical model is built that addresses all of the software project's
required functionality and that model is then extended to determine the
project's size.
However, whereas in a Function point Count where leaf nodes in the model correspond
to Logical Transactions (Transactional Function Types) and the
project is sized in IFPUG Function Points, in a Use Case
Point Count leaf nodes in the model correspond to Use Cases or Actors and
the project is sized in Use Case Points.
As with a Function Point Count, you can use component nodes to structure
your Use Case Point Count in any manner that is relevant for your project.
Figure 1 shows a hierarchical model for a Use Case Point Count that first
decomposes the count into Use Cases and Actors and then further decomposes
the Use Cases into a number of categories. The leaf nodes in the model
are named to indicate the Use Cases or Actors to which they refer.
Hyperlinks can be added to each each leaf node to link it back to its
source.
Figure 1
The type and complexity of each Use Case and Actor in the model is represented using the WORKBENCH Label 'UCPTYPE'. In order for your Use
Case Point Count to be sized and reported correctly it is critical that this
Label be properly set up. Figure 2 shows the required Label
attributes and options:
Figure 2
The 'UCPTYPE' Label is linked to each Use Case and Actor leaf node in the
model. Figure 3 shows the model after the Label has been linked and
the Label display has been turned on and set to the 'UCPTYPE' Label.
Figure 3
Sizing and Reporting a Use Case Point Count
The Function Point WORKBENCH™ - Publisher tool is used to size and
report your Use Count Point Count.
Firstly, within the WORKBENCH, output your count as a XML document using the
menu item 'Reporting | Output to fsmML ...'. Ensure that the fsmML
level of the generated XML document is set to 'Level 3'.
Next, within Publisher, select the generated XML document and one of the Use
Case Point report templates and generate the Use Case Point report.
See Figure 4.
Figure 4
Two different Use Case Point report templates have been developed.
-
The 'Use Case Point Summary' report decomposes the count's size in terms of
the Use Case Point types and complexities. See Figure 5.
-
The 'Use Case and Actor List' report lists all of the Use Cases and Actors
within the count. See Figure 6.
Variants of these two reports are included for both new development and
enhancement counts.
Additional Use Case Point reports could be developed either by
modifying existing or creating new Publisher report templates.
Figure 5
Figure 6
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