As always, this question arises from time to time: ‘To Task or not to Task ?’
Here is the answer from SAI:
Some teams break each story into tasks. As the tasks are identified, team members discuss each one: who would be the best person(s) to accomplish it, approximately how long it will take (typically in hours), and any dependencies it may have on other tasks or stories. Once all this is understood, a team member takes responsibility for a specific task or tasks. As team members commit to tasks, they reduce their individual iteration capacity until it reaches zero. Often, toward the end of the session, some team members will find themselves overcommitted, while others will have some of their capacity still available. This situation leads to a further discussion among team members to evenly distribute the work.
While breaking stories into tasks is fairly common, it is optional and not mandated in SAFe. It is mostly used by new teams to better understand their capacity and capabilities, and over time becomes unnecessary, with the team planning only at the story level.’ — Scaled Agile Inc. (SAI).
And some more…guidance…on:
To task or not to task?
Anti-pattern — when iteration planning is being done — story vis-a-vis tasks: