Asana is a task management web application that is flexible enough to handle your personal tasks all the way to a company with multiple departments and projects.
The interface and workflow is a typical task list that can be grouped into projects and then those projects can be grouped into workspaces.
Asana does not have a specific workflow in mind and is more suited to low level items as tasks do not have completion levels and are either done or pending.
Pro Very polished interface
Teams can have private (only visible to project members) and public (visible to anyone in the team) projects. Each member can also have their own personal projects.
Tasks can be viewed in list and calendar views. It's possible to display only the tasks assigned to the user or tasks organized by project or team. Single tasks can exist in multiple projects. Lists of tasks can be divided into sections and organized in many different ways – tasks that still have to be done, tasks that have been completed, by due date, by assignee, by popularity, etc.
Expanding a task will allow adding things like subtasks, tags, and attachments, as well as comments. Users can also subscribe to a task via RSS from this view. There's a separate view specifically for attachments.
Pro Simple workflow
The Asana task workflow within a project is broken down into "Today," "Upcoming," and "Later." The tasks themselves have the status of either done or not done. There is also a subtask feature to group tasks together. Tasks can be assigned to other team members and are stored in the "Inbox" view for processing. This replaces email for some team communication.