If I got it right you need the software product which allows multiple users to access the common database simultaneously to plan, track and report tasks.
We have 2 products for team collaboration:
1. VIP Team To Do List allows planning tasks for team members and sending to do lists to team members by email.
2. VIP Task Manager allows both sending tasks by email and multi-user simultaneous access (actually this product was developed on request of VIP Team To Do List users who wanted to share the database in real time).
I believe VIP Task Manager suits your needs better. You can learn more about VIP Task Manager and download 30-day trial version here:
http://www.taskmanagementsoft.com/
VIP Task Manager has 2 editions: Standard and Professional. Standard is more like VIP Team To Do List in simplicity, while Professional has more advanced features.