Clarification needed - Nexus Guide

The Nexus Retrospective has 3 parts - the second part is for addressing issues raised from the first part. Is this the only activity that they have to undertake. Even though it has not been mentioned explicitly (lest I missed that) I believe they can talk about internal team matters too (guided by Scrum), that can be addressed and rectified?

The second part of the Nexus Retrospective is not for addressing issues raised from the first part.

The first part of the Nexus Retrospective is a cross-team review of impediments and issue during the Nexus Sprint. The second part is a standard Sprint Retrospective for a single team that is participating in a Nexus, but they have an additional input - the issues that arose across teams. The output of the second part is a set of actions that could address the issues from either the first part or the second part. The third part is taking the set of actions from each individual Scrum team and making a visible, transparent plan for improvement.

During the second part of a Nexus Retrospective, it is expected that teams not only discuss issues that cross team boundaries, but also conduct a traditional Sprint Retrospective that focuses on improving the team.

2. Under Nexus Sprint Retrospective (pg 9) - it has been mentioned - "...every Retrospective..." - will that not mean every part of every Retrospective?

Those questions should be addressed through the entire Nexus Retrospective. It may be useful to talk about them in the first part to identify cross team issues and to talk about them in the second part to identify a team's contributions to the Nexus. In the first part, the context is the entire Nexus. In the second part, the context is an individual Scrum Team. The answers should be used to identify actions at both a Nexus and a Scrum Team level, which are planned for in the third portion.

3. Are not the individual scrum team Sprint Backlogs not considered part of Nexus artifacts?

No. Sprint Backlogs are part of the Nexus artifacts. In the definition of Nexus, it explicitly states that the artifacts include the Nexus Sprint Backlog and that all Scrum Teams maintain their own Sprint Backlogs. The standard Scrum Team artifacts exist in Nexus as they do in Scrum.

4. Nexus Sprint Backlog (pg 7) - para 2 - "During Nexus Sprint Planning, appropriate representatives from each Scrum Team validate and make adjustments to the ordering of the work as created during Refinement events. All members of the Scrum Teams should participate to minimize communication issues." - the statement moves from 'appropriate' to 'All members'. I believe it must remain - 'appropriate'.

I believe this is correct. Earlier, in the definition of the Nexus Process Flow, it also states that "appropriate representatives" participate in the Nexus Sprint Planning. I don't think that it makes sense for all members of the all the Scrum Teams to participate in the Nexus events.

5. The refinement event in itself seems to overlap with Nexus Sprint Planning. Should they still remain independent? Are they independent?

There are two levels of refinement.

First, the Product Backlog (of which there is one) is refined. This makes each Product Backlog Item a thin "vertical slice" of functionality with cross-team dependencies minimized. Any dependencies that can't be removed are identified. The team that is intended to do the work is also identified.

The team, which is following Scrum, can refine appropriately. However, there is some risk if a team begins to refine their allocated Product Backlog Items early. They could be reassigned to a different team. The latest possible time to decompose a Product Backlog Item into its work is at Sprint Planning, therefore it probably makes sense to defer the refinement with a team's portion of the Nexus Sprint Planning. One team's decomposition may not be applicable to another team, so it doesn't make sense to risk the wasted effort.

Thanks for the answers @Thomas Owens. My further comments:

1. Makes sense. This has been further elaborated in The Nexus Framework book - Pg 16, under Nexus Sprint Retrospective.

2. Agreed

3. The Nexus Framework book - Pg 8-9 mentions explicitly that Nexus extends Scrum - it has one additional artifact and 5 additional events and one additional role. Hence, I agree with your point. Thanks.

4. Agreed. 'appropriate' makes more sense.

5. Thanks for the explanation. Now it makes more sense that they in fact remain separate.

Additional query - 

The Scrum Guide mentions - "The Product Owner is responsible for maximizing the value of the product resulting from work of the Development Team."

The Nexus Guide mentions - "The Product Owner is responsible for maximizing the value of the product and the work performed and integrated by the Scrum Teams in a Nexus."

The Nexus Framework book - Pg 11 mentions - "The SM is accountable for maximizing the value delivered by the Development Team."

I know accountable and responsible are two different words, but above statements confuse me. Is not the value delivered in the form of product? Hence the statement of the book is wrong?

Thanks,

V