This paper mostly deals with the analysis of key performance indices. In the introduction the key performance indices (KPI) are described in more detail. In addition, SMART analysis is presented as a key component in the process of successful KPI selection. The KPIs are then divided into smaller groups, with particular with particular emphasis paid to their economic indicators. Other important indicators are also discussed, without which the entire analysis would be incomplete. The main part of the paper describes the KPIs of several Croatian companies in the manufacturing sector. The paper focuses mainly on larger companies and shows analyses from different years to illustrate that the analysis of KPIs is a process that takes place on a regular basis, and not overnight. This statement is supported by the examples of five Croatian companies from various manufacturing sectors, each of which is currently a leader in its sector on the domestic market. The analysis is conducted without revealing the names of the companies, as the data is not publicly available, and confidentiality agreements have been signed. This part of the paper also presents three examples of performance indicators, calculated according to the European Union regulations regarding the European Union’s 2021 Strengthening of Competitiveness Project (KK. 11.1.1.01 – version 2). Lastly, the observed companies are categorized and compared using the inferential statistics method. An in-depth analysis of the interdependence of the economical (income/-profit) and productional KPIs (OEE, WIP, takt time, cycle time and lead time) is made and presented in tables as to reach a conclusion more easily.