The Nexus Framework is a Scrum-based approach designed to help coordinate the effects of applying Scrum in Software Development at scale. It is essentially an exoskeleton that rests on top of multiple Scrum teams, enabling them to collaborate more effectively. This model ensures application of the Scrum theory and rules to multiple teams working together on the same project and aims to identify dependencies and remove cross-team impediments. The Nexus Integration team, a role unique to this framework, is responsible for managing dependencies, both within and outside of the Nexus.

Scrum@Scale framework is designed to scale Scrum to the organizational level, it naturally extends the core Scrum framework. It is an approach to deploy Scrum across an entire organization, whether that means scaling down to minimal viable bureaucracy, or scaling up to thousands of teams. The Scrum@Scale framework can help you to design your organization around the minimum viable bureaucracy for your context. This framework has two major components: Scalable Product Owner to manage multiple teams working on the same product, and Scalable Scrum Master to coordinate an ecosystem of teams.

LeSS is an approach that extends Scrum principles to large-scale and multisite product development projects. This framework was created to scale up the benefits realized from single-team Scrum like transparency, empirical process control, decentralized decision making, etc. to a larger organizational context. It mainly suggests organizing several Scrum teams around one product backlog to work on a common product increment. LeSS reduces the organizational complexity by descaling and eliminating unnecessary allocations, roles, artifacts, and processes. It emphasizes more on a systems thinking approach to optimize the whole system rather than individual parts.

The Scaled Agile Framework or SAFe is an enterprise scaling framework that provides a knowledge base of integrated principles, practices, and competencies to help organizations deliver high-quality and reliable software and systems at the fastest sustainable rate. This framework combines the elements of Agile development, Scrum methodologies, and Lean product development. SAFe provides an approach to scale Agile from the team level to the program and portfolio levels. It addresses complex issues that large organizations face, such as strategy, investment funding, architecture, integration, roles, and responsibilities.

The Spotify model, although not a framework, is a people-driven, autonomous approach for scaling Agile and Scrum that has been used as a reference model by many organizations. In Spotify’s model, autonomous squads of no more than eight members each are responsible for different aspects of the product. While each squad essentially operates as a Scrum team, the model also introduces additional roles such as chapters, tribes, guilds, and alliances in order to foster knowledge sharing, alignment, and quality control across the organization.

Disciplined Agile Delivery (DAD) is a process-decision tool kit that focuses on the deployment of Agile projects in enterprise settings. DAD extends the Scrum lifecycle to include upfront and tail-end activities such as modeling, documentation, and governance not typically included in basic Scrum. The framework provides flexibility to use various lifecycle models like Agile, Lean, continuous delivery, and exploratory. It follows a goal-driven approach where teams can make decisions based on their unique needs.

MetaScrum is a communication forum that unites all of the Product Owners of the Scrum Teams on a program. Its purpose is to facilitate coordination and prioritization of resources and activities. It is a meeting place where the Chief Product Owner presents an overview of the product strategy, trends and customer feedback to the PO Team in order to align the PO Team to the Vision.

Enterprise Scrum is a business-oriented, scalable, general-purpose Scrum framework for managing complex work that requires considering multiple levels in the organization. It is important for the implementation of Scrum practices on a large scale. The scrum framework includes various tactics, strategies, and principles for implementing Scrum at the enterprise level. This can include managing and strategizing product development, Marketing, Sales, and organizational transformation. As part of this framework, multiple Scrum teams work together with precisely defined roles and routines. Enterprise Scrum encourages an exponential growth mindset while focusing on value creation.

Multiple team Scrum is another concept employed to address the challenges of scale. In this approach, different Scrum teams work on parts of the same product backlog, synchronizing their work as needed. This leads to the creation of a potentially shippable product increment at the end of every Sprint. The aim is to keep the focus at the product level rather than individual teams, which need to ensure regular and effective communication. Clear definitions of done and solid alignment on cross-team issues and dependencies are key parameters for success in this approach.

The Water-Scrum-Fall Model is a hybrid agile approach that involves using a combination of waterfall and Scrum methodologies to gain the benefits of both. This model aims to achieve more flexibility and agility of Scrum along with the structure and predictability of the Waterfall model. In this model, the requirements and design phases are done in a traditional waterfall manner, and then Scrum methodology is used for the development and testing phases. The final phases of delivery and maintenance are again done in the waterfall model.

Feature Teams are cross-functional and cross-component teams that are able to pull off backlog items and work on them independently. This methodology divides large-scale projects into several smaller features which are then assigned to different teams. The teams operate simultaneously on different features, which, when done, will be integrated into the final product. This division allows for work to be carried out in parallel, and it increases the teams' capacity to handle backlog items.

The Product Owner team concept suggests the collaboration of multiple product owners who work together to provide a synchronized view of the product vision to multiple Scrum teams. This is especially relevant in large organizations where a single product owner may not sufficiently handle the backlog for all teams. The goal of the product owner team is to maintain the product backlog, ensure that priorities are aligned, and that all teams have a clear understanding of the items in the backlog. This approach helps in maximizing the value delivered by multiple teams working together.

Multi-Team Product Backlog Refinement refers to the practice where representatives from multiple Scrum teams jointly refine the product backlog. This approach is particularly useful when multiple teams are working on the same product. It helps in identifying interdependencies among teams, resolving conflicts in understanding, and achieving a uniform direction across all participating teams. It also provides an opportunity to discuss the design and technical decisions impacting the product on a broader level.

In the context of Scaling Scrum, Continuous Integration (CI) is an essential practice. CI is a development practice where developers integrate code into a shared repository frequently, preferably several times a day. Each integration is then verified by an automated build allowing teams to detect problems early. By integrating regularly, organizations can detect errors quickly, and locate them more easily. This leads to better collaboration between teams and ensures early feedback on feature development, which is extremely beneficial in a scaled Scrum environment.

Communities of Practice (CoP) denotes a group of people who share a craft or a profession. In a Scaled Scrum setup, CoPs provide a platform for Scrum Masters, Product Owners, and team members to share knowledge, learn, and improve their skills. It's a forum where individuals can solve problems, discuss new ideas, share best practices and propagate the Scrum values and principles across the organization. This leads to consistent understanding, better collaboration between teams, and a more robust Scrum practice.

WaterScrumFall is a hybrid model that aims to blend Waterfall and Scrum methodologies. It is often used in large organizations which require the structure and certainty of the Waterfall model, along with the flexibility and adaptivity of Scrum. Typically, the front-end activities like budgeting, analysis, designing and the back-end activities like integration, testing and maintenance are done in Waterfall manner, whereas the iterative development is performed in the Scrum manner. It provides a balance of control and agility while managing the risk.

Scrum-ban is a Scrum and Kanban hybrid that applies the principles of Scrum in a Kanban system of work. It is ideally suited for projects that require continuous maintenance, involve frequent changes or have no certain end date. It provides visual management by limiting the work-in-progress (WIP) items, which helps in reducing the time taken for an item to travel through the process. It maximizes efficiency, optimize flow and also speeds up delivery process.

Professional Scrum with Kanban (PSK) is a course that teaches Scrum practitioners how to apply Kanban practices within their Scrum teams, without changing Scrum. It involves visualizing work, limiting work in progress and actively managing work items, in a way that complements the Scrum framework. PSK enables Scrum teams to define, identify and optimize their workflow, improve their deployment practices, get more accurate data for inspection without disrupting ongoing Scrum practices.