Every Scrum Team Member should be working on tasks in the Sprint Backlog. Generally speaking, this should be one task at a time with little or no work done on work that is not on the Sprint Backlog. The visibility of the Sprint Backlog is an important part of Transparency within the Scrum Team. As well, doing one task at a time helps with Focus, another of Scrum’s values. If team members follow this rule, then the work of the Sprint is done in a reliable way. When team members take on multiple tasks simultaneously or when they take long breaks to do non-Sprint Backlog work, then the team’s focus is substantially diminished and overall productivity suffers.