The Scrum Guide and the SBOK side by side: a map

People who learn Scrum from one source and then meet the other are often confused for the first hour. The words are different, one document is a dozen or so pages and the other runs to hundreds, and each seems to say things the other does not. They are not rivals. They answer different questions, and once you see how, moving between them is easy.

Two different jobs

The Scrum Guide is a definition. It describes the framework's minimum: a Scrum Team of one Scrum Master, one Product Owner and Developers; five events inside the Sprint; three artifacts, each with a commitment; and the theory underneath, which is empiricism and lean thinking. It says the framework is purposefully incomplete, defining only the parts required to implement Scrum theory, and that other practices are built on it.

The SBOK® Guide, in its Fifth Edition, is a body of knowledge for running projects with Scrum. It has six principles, five aspects (organisation, business justification, quality, change and risk) and, at its centre, nineteen fundamental processes grouped into five phases. It also covers how to scale Scrum for large projects and for programs and portfolios. It adds a good deal the Guide leaves out on purpose, such as business case, charter, release planning and formal acceptance.

Using both is common. The Guide tells you what Scrum is. The SBOK suggests how an organisation might do all the surrounding work.

The nineteen processes, in plain words

Here is each SBOK process with the nearest Scrum Guide idea, as we read them. The match is approximate. The two were not designed to line up one for one.

Initiate

Plan and Estimate

Implement

Review and Retrospect

Release

Where they agree

On the heart of it, they agree. Both want a small, cross-functional, self-organising team. Both want work in fixed-length Sprints that end with something usable. Both want a Product Owner who orders the work, and a Scrum Master who serves and coaches. Both rest on transparency, inspection and adaptation, which the SBOK calls empirical process control. Both say that the Daily Scrum or Standup is short, and that the Sprint Review and Retrospective come at the end.

Our post on empirical process control explains the shared theory.

Where they differ

• Scope. The Guide stops at the team and its Sprints. The SBOK starts earlier, with the business case, and ends later, with releases and closure.
• Vocabulary. "Developers" in the Guide are "the Scrum Team" in the SBOK, and the Guide's "Scrum Team" is the SBOK's "Scrum Core Team". See the Scrum Team.
• Commitment. The Guide has the Developers forecast and commits them to the Sprint Goal. The SBOK has the team commit to stories.
• Acceptance. In the SBOK, the Product Owner accepts or rejects each story against acceptance criteria. The Guide has the Definition of Done decide what is in the Increment.
• Extra artifacts. The SBOK has a Definition of Ready, a project charter, a release plan, an impediment log and a Scrumboard. The Guide names none.
• Time-boxes. The review and retrospective are one hour per week of Sprint in the SBOK, and up to four hours and three hours for a month in the Guide.
• Optional roles. The SBOK adds non-core roles such as a Scrum Guidance Body, which has no counterpart in the Guide.
• Scaling. The SBOK has chapters for large projects and enterprises. The Guide says only that a team that grows too large should split into several, sharing one backlog and one Product Owner.

Which should you use

You do not have to choose. A few suggestions:

• Learning. Start with the Guide, then read the SBOK for the surrounding practice.
• Studying for an exam. Know both, and know which document a question is asking about. Terms differ.
• Running a team. Use the Guide as the rules of the framework and the SBOK, or any other source, as a menu of practices.
• Writing to a client or auditor. Say which source you follow. "We use Scrum as defined in the Scrum Guide, with release planning and acceptance practices from the SBOK" is clear and honest.

None of this makes either document more correct. One defines a framework and the other advises on using it.

A note on editions

Both documents change. The Scrum Guide's current edition is dated 2020, and the SBOK discussed here is the Fifth Edition. Older material uses different names: for example, the process now called Refine Prioritized Product Backlog was once called grooming, and older Scrum Guide editions spoke of a Development Team. When you meet an unfamiliar term, check the edition before assuming a disagreement.

How to practise it

The simulator follows the SBOK's flow of five phases and eighteen steps and keeps the Guide's events and accountabilities in each one. It is a way to see how the two fit together in a single project.