Which two statements are true regarding the nature of large-scale product development with Scrum? (choose the best two answers)

In large-scale product development, managing dependencies and maintaining team focus are critical for success. A well-structured Product Backlog, where work is refined to be as independent as possible for each team, directly minimizes cross-team dependencies. This reduces the need for developers to split their time and attention across multiple teams to resolve issues, thereby promoting team stability and focus. Furthermore, the principle of reducing context switching is paramount. A person working on multiple Scrum Teams simultaneously incurs significant cognitive overhead, leading to reduced productivity and effectiveness compared to a developer who can focus entirely on the goals and work of a single team. This loss of productivity is a well-documented phenomenon in knowledge work.

B. The Scrum framework is immutable. Scaling frameworks like Nexus are built upon Scrum as a foundation; they add coordinating roles, events, and artifacts but do not change the core rules of Scrum for each team.
D. The Scrum Guide emphasizes commitment and focus but does not mandate that team members must be "full-time." A person can be a dedicated and effective part-time member of a single Scrum Team.

1. The Nexus™ Guide (July 2021):

In the section "Nexus Framework," it states, "The Product Backlog needs to be decomposed so that dependencies are identified and removed or minimized." (p. 6). This supports option A, as minimizing dependencies through backlog structure is a key practice to enable teams to work without members needing to be shared.

The guide also states, "Nexus is a framework... It uses Scrum as its building block." (p. 3). This reinforces that Scrum itself is not changed, refuting option B.

2. The Scrum Guide™ (November 2020):

"The Scrum framework, as outlined herein, is immutable. While implementing only parts of Scrum is possible, the result is not Scrum." (p. 3). This directly refutes option B.

"Scrum Teams are cross-functional, meaning the members have all the skills necessary to create value each Sprint." (p. 5). This ideal is undermined when individuals are split across teams, which supports the reasoning for option C.

3. Weinberg, G. M. (1992). Quality Software Management: Vol. 1 Systems Thinking. Dorset House.

Weinberg's research on context switching demonstrates that even splitting attention between two tasks can result in a 20% loss of time to overhead. For three tasks, it's nearly 40%. This foundational work in software management provides strong evidence for option C, showing that a person on multiple teams is significantly less productive. (Chapter 15, "Managing the Project," discusses the cost of task-switching).