This document discusses COCOMO cost drivers, which are product attributes that can affect the effort required to develop software. It describes three key cost drivers: reliability (RELY), database size (DATA), and product complexity (CPLX). RELY depends on how critical software failures are, from slight inconvenience to risking human life. DATA is based on the ratio of test database size to source code size. CPLX has six levels based on factors like control operations, computational operations, and user interface complexity. Tables provide examples and effort multipliers for each cost driver.