Scaling Scrum with Nexus in VSTS

In this post, I will cover what Scrum Nexus is, where, when, and why you would want to use it, and how to set up VSTS best to accommodate your Scrum practices. As VSTS’s tooling is not yet perfect for some of Nexus’s practices, I will discuss some viable fallbacks and workarounds.

Background – Why Scale?

Scrum.org’s official Scrum guide defines Scrum as “A process framework used to manage complex product development”. Scrum’s events, artifacts and rules revolve around a Scrum team, which consists of a Scrum Master, Product owner, and 3-9 development team members (a.k.a. developers).

This limit on team size is important. For Scrum to succeed, the team must consist of developers who can cover all the work required for the product to be delivered at the requisite quality level. If, however, there are fewer than 3 developers, the team is likely to miss some skills required to deliver the product. More than 9 team members, will require too great an effort to coordinate, and result in an unmanageable process.

Therefore, when delivering a large product, as is often the case in enterprise-level projects, the organization must scale beyond the single Scrum team. A framework is required to manage and coordinate the work of multiple Scrum teams.

Enter Nexus.

What is Nexus?

Scrum.org defines Nexus as “an exoskeleton that extends Scrum to guide multiple Scrum team on how they need to work together to deliver working software every Sprint”. While there are other systems out there for scaling Scrum, from a simple (and somewhat naïve) “Scrum of Scrums”, where Scrum Masters get together to coordinate the teams’ interdependencies, to full blown complex frameworks such as SAFe, I tend to prefer working with Nexus, as it is a simple extension of Scrum. It builds upon the knowledge that teams have working with Scrum, and applies the same processes, artifacts, and roles, to a larger scale, introducing minor tweaks, rather than new complex mechanics.

Nexus revolves around the notions that teams minimize risk by minimizing interdependencies. A special integration team (called the Nexus Integration Team, or NIT) is formed. The NIT is responsible to uncover and manage whatever dependencies exist between teams’ work items, by eliminating or carefully controlling their impact. The NIT is also responsible to guide the Scrum teams towards continuously integrating their work, to reduce the risk that comes from large integrations at the end of a sprint or a release.

The Nexus Integration Team members include cross-functional developers, such as the product’s DBA, build-master, architects, technical writer, and anyone who may be of greater use the organization as a coordinator of the integrated product, than a member of one Scrum team. The NIT has one Scrum Master, who depending on the teams, may be the one Scrum Master for the entire product, or just for the NIT. In any case the product must have one, and only one, product owner.

Setting up VSTS for Nexus

The Team Project

First things first – There should be one and only one team project for the entire product. You want to be able to view the entire backlog, measure, query, and track progress for the entire product, and you want to be able to view charts and reports that aggregate data for the entire product. If you separate the product so that each team has its own “Team Project”, you will not be able to do so. The Work tracking and dashboard capabilities of VSTS are limited by scope to a single Team Project. You cannot split a backlog, or visualize a Kanban board across multiple team projects.

This choice does have some limitations – the entire product, including all of its teams will have to follow the same process template, though if you have already decided to follow Scrum and Nexus, this should not be an issue.

Areas and Iterations

One Set of Iterations for All Teams

According to the Scrum guide, if you have multiple teams working on the same product, they should be delivering together on the same cadence. In VSTS, this means that there should be a single iteration cadence that all teams follow. All teams start together and end together because the integrated product increment is delivered at the end of every sprint.

The Nexus Integration Team is the Default Team

In VSTS the default project team has the project root as its area. Each of the other teams get an area under the project root:

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The NIT Includes all Sub-Areas

In Nexus, there is a unique event that is added to all other events that normally occur in Scrum. This event is called the Nexus Sprint Planning session. In this meeting, the product owner and the NIT review the upcoming work and coordinate what PBI will be addressed in which sprint, by which team. In addition, the Nexus Integration Team is responsible for coordinating of the integration of all teams’ work, on a daily basis.

In order to accommodate these needs, the NIT’s backlogs and boards will be configured to view not only the work items (Epics, features, and/or PBIs) that are in the NIT’s area (the root area for the project), but also the work in each of the areas beneath it, i.e. work that has been associated with the Scrum teams.

This way, the integration team can visualize all of the PBIs on their board, and be ready whenever a PBI is ready for integration (e.g. moved to a column entitled “Integrate” – you will want to create this column).

Setting Up the Nexus Sprint Backlog

As previously mentioned, one of the NIT’s primary responsibilities is to coordinate work among the Scrum teams in order to mitigate interdependency risks. A commonly used tool is called the Nexus Sprint Backlog. The Nexus backlog is views the PBIs in a two-dimensional grid, where they look at each team’s sprint backlog for the upcoming and next few sprints. They then identify and mark each dependency, and note how risky it is:

· When interdependent PBIs are handled by different teams (e.g. 1 & 5, below), the risk is greater than when both PBIs are handled by the same team (e.g. 1 & 4) because coordination is more complex.

· When PBIs are not only handled by different teams, they also are expected to be completed in the same sprint (e.g. 4 & 5), the urgency requires greater coordination, and the risk is even higher.

· When there is a dependency on a PBI by someone outside the project, the risk is greater because there is likely to be an important commitment (e.g. 8). This risk goes up even further, if the PBI is needed by the end of this sprint (e.g. 9)!

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While there is no Nexus Sprint Backlog in VSTS, as of the writing of this post, Microsoft’s Delivery Plans extension goes a long way towards giving us just this visualization. It is available in the marketplace so you can install it and use it to visualize your work across teams and sprints:

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Visualizing Dependencies in VSTS

The delivery plans extension does not have the ability to visualize and track dependencies between backlog items. Yet. The product group has mentioned that this capability is on the roadmap, but I cannot confirm when this will be delivered.

In the meantime, we need to come up with a way to mitigate this drawback.

Work Item Relationship Links

One thing that you can do is mark a work item to be the predecessor of another. To do this, simply open the PBI, and under Related Work, click Add link to an existing work item. Select the work item that this work item depends upon:

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While this will set the work items’ interdependencies, this will not show up in the plan. At least not as of today.

Tags

While this requires some manual work, I would suggest adding tags marking an item as “cross team dependent” or “external dependency”. Tags do show up in the plan and can augment it to give the NIT an at-a-glance idea of the risk involved with this project. Note the tags marked by the arrows in the screenshot below:

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Summary

We have seen how teams wishing to use Scrum and Nexus to drive their development efforts, can set up VSTS to visualize and track their work. The following is a checklist for everything that you need to do:

1. All teams including the integration team work in the same Team Project

2. The Integration Team is the default team

3. The integration team’s area is the project root (e.g. \MyProject)

4. The Scrum teams’ areas are set under the integration team’s (e.g. under \MyProject\ScrumTeam1)

5. The integration team’s area should include all sub-areas

6. Add a column board entitled “Integrate” to mark PBIs that are ready to be integrated with the entire product

7. Install the Delivery Plan extension if it isn’t already installed for your account

8. Set up a delivery plan to include the Scrum teams and their sprints

9. Use the Predecessor link type to denote a dependency

10. Mark the kind of dependency with a tag, so that it can be seen in the plan.

I hope you find this useful. If you have found other tip and ideas to help drive Nexus, please share them with us!

Thanks,
Assaf

About Assaf Stone

My name is Assaf Stone. I'm a senior ALM consultant in Microsoft's Premier Support for Developers Team. When not being kept busy by work, my wife, or my four kids, I like to practice archery, read books, and listen to 70's and 80's rock music. I would also like to just relax, if I had any more spare time!
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  • Rodrigo Almeida de Oliveira

    Great article Assaf! Congrats!