Open Workbench is project management software. It allows you to manage the key aspects of a project - specifically to manage tasks, place tasks into phases and manage the allocation of resources. This will allow you to schedule a complex project with many resources (people) effectively to allow it to be completed to deadlines.
This is particularly important because you have a number of resources to manage and many tasks to complete, some of which are clearly dependent on other tasks (you can't test the content until the interface has been produced, for example).
Wikipedia has a really quite useful page on project management and what it is. It's worth a look.
There's also a Wikipedia page on Open Workbench itself, although it's rather less useful.
Specifically Open Workbench will allow you to:
- produce Gannt charts
- assign resources and manage them and produce a resource overview
- produce a critical path analysis
A quite useful definition of project management is:
“Project management is the process by which projects are defined, planned, monitored, controlled and delivered such that agreed benefits are realised. Projects are unique, transient endeavours undertaken to achieve a desired outcome. Projects bring about change and project management is recognised as the most efficient way of managing such change.”