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.