Nexus events: Team Sprint Planing & sequence of events

I understand it that way, that the Nexus Sprint Planing replaces the Team Sprint Planing. Right?

The Nexus Guide says that events are appended to, placed around, or replace regular Scrum events to augment them. It also says the result of Nexus Sprint Planning includes a Sprint Goal and a Sprint Backlog for each Scrum Team.

If Nexus Sprint Planning replaced the Sprint Planning event in each team, how would those Scrum Teams then arrive at their own Sprint Goal commitment and the forecast of work for achieving it?

The 2021 edition of the Nexus Guide doesn't define what the Nexus Sprint Planning looks like. Previous editions of the Nexus Guide divided the Nexus Sprint Planning into two distinct sections. In the first section, representatives from each of the Scrum Team would adapt the work that has come out of the most recent refinement events (Cross-Team Refinement is an event in Nexus). The Product Owner and these representatives craft a Nexus Sprint Goal and what the overall objective of the Nexus is. Each Scrum Team then performs their own Sprint Planning, creating their own Sprint Goal that supports the Nexus Sprint Goal and Sprint Backlog, making sure the other teams in the Nexus are aware of any dependencies that were discovered during Sprint Planning.

The output of Nexus Sprint Planning is the Nexus Sprint Backlog, which is the Nexus Sprint Goal and the Sprint Backlogs of each of the Scrum Teams in the Nexus. Each Scrum Team maintains their own Sprint Backlog, but the Nexus Sprint Backlog makes the work, including dependencies, visible to all teams in the Nexus.

Nexus Sprint Planning replaces Sprint Planning in the sense that Nexus Sprint Planning is a container for both planning across the Nexus as well as each individual team's Sprint Planning. The Nexus Sprint Planning event is not complete until all the teams have completed their own Sprint Planning sessions.

Previously, the Nexus Guide did recommend an order for events. The Nexus Sprint Planning would come before each team's Sprint Planning. The Nexus Sprint Retrospective would be the full Nexus, individual teams, then the full Nexus again. The Nexus Daily Scrum also defines two-way information flow. However, as far as I can tell, all these recommendations are gone. You could conceivably organize these events in different ways and still be doing Nexus.

The Nexus Daily Scrum comes before the teams Daily Scrum so that the team can plan to address any dependency or integration issues raised during the Nexus Daily Scrum.  This is obviously not the only time dependency & integration problems can be raised.  

The only Scrum event that is replaced by a Nexus event is the Sprint Review.  All others are augmented.  

The Nexus Sprint Retrospective would be the full Nexus, individual teams, then the full Nexus again.

@Thomas: Is this still the case in the updated Nexus guide, since I think I can't find any hard evidence any more in the Nexus Guide of the three sections. They are some 'additions' described, but no longer three parts.

From the Nexus 2021 guide: 

Nexus Sprint Retrospective

The purpose of the Nexus Sprint Retrospective is to plan ways to increase quality and effectiveness

across the whole Nexus. The Nexus inspects how the last Sprint went with regards to individuals, teams,

interactions, processes, tools, and its Definition of Done. In addition to individual team improvements,

the Scrum Teams’ Sprint Retrospectives complement the Nexus Sprint Retrospective by using bottom-up

intelligence to focus on issues that affect the Nexus as a whole.

The Nexus Sprint Retrospective concludes the Sprint.

As Nexus does not replace the teams Sprint Retrospectives, it still makes sense that the Nexus Sprint Retrospective has three parts as per the 2018 guide.

@Thomas Ownes 

I have a problem with understanding time boxing Nexus Sprint planning event. 

You mentioned:

Nexus Sprint Planning replaces Sprint Planning in the sense that Nexus Sprint Planning is a container for both planning across the Nexus as well as each individual team's Sprint Planning. The Nexus Sprint Planning event is not complete until all the teams have completed their own Sprint Planning sessions.

It means that there is 2 options:

A: All sprint planning events  summary has got only 8 hour timebox (for 1 month Sprint) 

B: Nexus Sprint planning has got 8 hours and each Sprint Planning  can also has got 8 hours (for 1 month sprint) for example - three scrum teams it will be maximum 30 hours of planning?