Various attributes of cost drivers used in COCOMO model are:
1. Physical attributes: These are concerned with needed characteristics of the software product being developed.
2. Computer attributes: These are constraints imposed on the software by the hardware platform. These affect software productivity due to effort must be expended to overcome the hardware limitations.
3: Personnel attributes: These are multipliers which takes into account the experience of the people who are working on the project.
4: Project attributes: These are concerned with the use of software tools, the project development schedule and the use of modern programming practices.