Agile project management welcomes changes in scope, but it also requires a trade-off of other items in the product backlog. The product owner owns the backlog and has to be able to make these decisions regarding trade-offs between stories and features. The project manager should guide the agile team to add the new scope to the product backlog and prioritize it according to the project goals and customer value. The project manager should also conduct regular backlog grooming sessions to assess and update the backlog items. The new scope should not be added to the current sprint, unless it is small enough to be completed by the time the sprint ends and does not affect the sprint goals. Creating a parallel sprint, pausing the sprint, or moderating the expectations for sprint quality are not agile practices and would compromise the project's agility, quality, and delivery. References:
* How Agile Addresses Changing Project Scope
* Agile Twists & Turns: How to Handle Scope Changes
* How to change your project's scope (the right way)
* Agile Scope Management: Refactor Your PMP