EN
A process of software development is highly specific and it is especially hard to manage quality in it. One of the tools in this domain is, described in the article, the CMMI (Capability Maturity Model Integration), which integrates good practices concerning products or services development and maintenance. The model also makes it possible to perform a rating on a scale of maturity levels. From the 4th maturity level (quantitatively managed), an organization is expected to have quantitatively (i.e. with the use of mathematical models) expressed quality goals and use them as criteria in managing processes. In the article, an effort estimation model for software development is presented.