I am running a project that is no longer viable due to an incorrect assumption. Therefore the project needs to be canceled/discontinued/killed/deleted/scrubbed. What is the correct name for this stage of a project?
The Project Management Perspective
This will vary by organization, and a lot depends on what you're trying to communicate. Formally, the PMBOK calls this stage the "Project Closeout Group" and says that it contains types of closures such as:
- Project Complete
- Project Terminated
- Premature Closure
From a more practical project management perspective, this phase of the project is generally just called "Project Closeout" regardless of the reasons you are closing the project. The key is to use the term that's most effective at communicating the project management stage and (if necessesary) the reasons for the closure to the project team, senior management, and the rest of the organization.
Other Roles, Other Terms
From a portfolio management or agile perspective, you might spin this as "reallocating resources to more promising projects," or simply state that your project has "correctly failed early." This positions the message within your organization, but it doesn't really change the fact the project management team must close out the project in some fashion, rather than simply dropping the plan on the floor and walking away.
Again, regardless of framework, communication is the goal. The name you use to designate the process is only meaningful in the context of communication with others, so your mileage will vary.