Staff Management Script / To Do list

We require a simple script to manage projects across several staff and outsource companies. It needs to work like the attached spreadsheet. As Administrator I can login and set up jobs that need to be done. I can then assign these to members of staff. The members of staff can login and change the status of the job as they complete it. They can also login and add notes to the project. The system needs to be flexible for upto 20 – 30 members of staff. We are looking for a solution in PHP and MYSQL Each project would have a serial number. The project could either be in an URGENT, or Regular list. Once complete the project goes to the complete section. The administrator needs a hidden field to make notes that the staff CANNOT see.