Hi,
Our company is following Capability>Epic>Story/task structure. Scrum can adapt task or subtask to get the user story completed. Story and Task are in the same level. Story can be a feature worked by many and a task can be a standalone tech task. I am trying to find if the scrum should use task or subtask to complete the story.
Method 1: User story breakdown by task. Break the epic in to smaller chunks of stories typically with SP 3,5,8 (S,M,L). In general our stories can be worked on by one person. It is further drilled down by tasks. Once the story is assigned to the person he/she will create task and associate the task to the story. The task estimates are given in hours and not more than two days. hours are logged in the task. One advantage is that there is movement in the sprint burndown every two days. Disadvantage is that there is ad-hoc task creation of two days and associating it to the story. Further the estimates in task is not calculated up to the story.
Method 2- User story breakdown by subtask. Story is estimated by SP and the subtask by hours estimate. Advantage is that it is neat, easy to identify the work and the estimates adds up to the Story. Disadvantage is that subtask does not get reflected in burndown chat.
Your feedback is greatly appreciated. :)