Use Case Complexity

[frankpadre]

Is there a way to add items to the Complexity menu for Use Cases? Specifically, we would like to add a 'Minimal' category (with a factor of '1') to indicate that the UC already exists (typically) and just barely needs to be touched for the current project. (We're using this for UC Estimation.)

I was hoping this would appear under Settings->Project Types->General Types, which seems to allow me to edit most other factors ('Difficulty', etc.), but Complexity is not there.

[Dermot]

Try: Settings | Project Types | Estimnation Factors

[RoyC]

The types of Complexity are defined by the Predefined Reference Data Tagged Value Type ComplexityTypes.

In the Help topics on Exporting Reference Data and Predefined Reference Data Tagged Value Type we state:
 
"Whilst complexity types can be exported and imported as project reference data, they cannot be directly updated and so are effectively standard across all projects."

There are, in fact, 5 possible values of Complexity: Easy, Medium, Difficult, Extreme and Unknown. You can omit or add the last two values by selecting a checkbox on the Objects page of the Tools | Options dialog.

I would use the Easy value instead of your proposed Minimal; in the Use Case Estimation calculations Easy has a value of 1, the same as you propose for Minimal. There would be no point in having different statuses with the same value, as the calculation would not distinguish between them.

[frankpadre]

Thanks Roy, but my 'easy' UCs are showing up as 5's, not 1's. Is there also an option to shift the values??

[RoyC]

No, the values are fixed too. On a brief investigation we cannot see how Easy would take a value of 5, so perhaps you could submit a bug report so that someone with a deeper understanding can check it out.

If Easy is being calculated as 5, Unknown would presumably be 1. If you have not looked already, could you enable the two extra values and set a UC to Unknown, and see if it is, in fact, calculated as 1?

[frankpadre]

Perhaps I'm misinterpreting something? I'm looking at the 'complexity' column in the metrics report. My 'easy' UCs show up as 5, difficult as 15. Unknown shows up as 25! Medium is 10, extreme is 20. Note that this corresponds to the order in the dropdown list, i.e., easy to unknown. There is no 1. I'm running 10.0.1007.

[frankpadre]

This also corresponds to your documentation...

 As you build your project using UML use cases to describe the proposed functionality, you should assign a rating to each use case:

    Easy (5 points): The use case is considered a simple piece of work, uses a simple user interface and touches only a single database entity; its success scenario has less than 3 steps; its implementation involves less than 5 classes
    Medium (10 points): The use case is more difficult, involves more interface design and touches 2 or more database entities; its success scenario has between 4 to 7 steps; its implementation involves between 5 to 10 classes
    Complex (15 points): The use case is very difficult, involves a complex user interface or processing and touches 3 or more database entities; its success scenario has over seven steps; its implementation involves more than 10 classes

[RoyC]

Yes. No. Maybe.  The problem here is that the Use Case Metrics calculations operate 'behind the scenes' and do certain things that you and I probably don't need to know about. One of those things, apparently, is taking the fixed values assigned to the complexity statuses (Easy = 1, Unknown = 5) and multiplying them by 5 before displaying that result in the Complexity column of the Use Case Metrics dialog.

If you are working through the GUI, all you need to know is that if you select a value of Easy in the Complexity field in a Use Case properties dialog, it gives you a smaller 'Sum of Complexity' and consequent values in the Use Case Metrics than if you select a value of Difficult or Unknown.

If you are working through the API, in the attributes of the Element Class, all you need to ensure is that the Complexity attribute provides the values 1 to 5 in correspondence to the field values Easy to Unknown.

In your case, firstly, to provide the effect of Minimal use Easy. And secondly, submit a feature request (using the link at the bottom of the page) asking for freedom to edit the Complexity field values and their numeric equivalents.

The documentation you quote is technically correct but it could be clearer. You assign the rating of Easy and the Use Case Metrics calulation transforms that into a numeric value of 5.