At the center of any project management approach—agile, or otherwise—is the plan: the list of tasks that your team is working on during an iteration. In addition to providing the team a focus, the plan also can help developers identify the goal of a coding episode , prioritize their work, and inform design and implementation decisions.
As a team, it is useful to be able identify how well an iteration tracked to the plan, both for retrospection and future planning. Being able to answer questions like "How much coding did we need to do to implement a feature?" and "Did we do much work beyond what we planned?" is useful in a retrospective to improve your process. Having an easy way to identify what work went into implementing a feature helps future planning by make it easier to estimate similar features.
Once the team is coding, version-management systems are at the center of a development team's collaboration process. You can use the version-management system in collaboration with your task-tracking process to help both developers and teams focus on high-value tasks by associating each commit to the version-control system with the work items for an iteration. If done correctly, this can help you work more productively. If done incorrectly, it can slow teams down and even distract from goals.
A prerequisite to having a tracking and planning process is to have a plan. A plan need not be heavyweight, and the planning process need not take an undue amount of time. Some developers—and even managers—consider planning a roadblock to actually "getting things done." But planning is an essential part of getting the right things done. Planning is simply identifying possible work, prioritizing it, and committing to the group of items to work during a development iteration.
The list of items for an iteration (the backlog) gives the team a focus. While having a plan does not preclude changes, it makes it clearer when there are changes, and enables all of the stakeholders to understand what to expect. The plan, then, is a list of backlog items that identify items of interest to stakeholders.
The plan provides a framework for the development team’s day—from deciding what to work on, to deciding what is worth discussing in the team's daily scrum (if you use Scrum). A useful way to help team members focus on the goal of delivering items off the backlog is to have a rule that, when committing code, you need to associate the commit as being part of an item off of the backlog.