Resolving Model Collisions

Before checking an edited model back into the version control repository, you will need to check your edits against any edits made by other authors in the latest model already checked in before your attempt to check in.

To do the model comparison between your local model and the model in the version control store, you should have already opened the version control store and have your local copy of the model open in the Use Case Editor.

Select File | Version control | DIfferences… from the main menu. This will compare every field in your model against the corresponding filed in the top checked in model of the version control system. Differences are highlighted in pink. Places where items are present in one of the two models but not in the other will be highlighted in pink on one side, and marked in gray a not being in the model alongside. An example of two models with a difference and a new item not present in the top version control model are shown below:

Differencing two requirements models

The left three columns of the difference view identify where in the model to look for the differing items. The rightmost two columns are the value held in your as yet unchecked in model, and its equivalent value in the latest checked in model of the repository. Your task is to make sure that what you finally check in is a model that resolves these differences to everyone’s satisfaction.

Many check ins will only have one or two inconsistencies that have to be resolved. In this case most of the rows in the difference view are the same. You can select View | Differences only from the View differences window menu and it will restrict the list to just those entries that have inconsistencies.

Note that in its current form, this View differences tool does not let you edit the items from within the View differences window. It is intended in a later version of the tool that you could select the left or right values, or edit one of them to resolve the differences. As of today, you have to return to the model by closing the differences window, and make your edits there.