What kind of UML diagrams can describe how a new feature will impact/affect an existing system?
For example; my usecase is we have an existing web application (system) that uses framework specific user login & authentication. We need to change the system to use OpenID to login and authenticate users.
We also want to document how this new feature will impact ancillary functionality of the system and thus estimate the work involved in implementing this feature.
- How will OpenID affect our profile update feature - it will make it redundant.
- How will OpenID affect our view previous sales orders - upon AJAX requests we will need to authenticate the user in a different way, we will need to associate a users openid id with a sales order from now on, etc.
Is there such a UML Diagram or Software Engineering document that is applicable to describe this?