Data Governance is one of the most important aspects of BI systems, that unfortunately seen less important in many organizations. All usefulness and gratefulness of BI system will only be seen if there is a good data governance in place. If you build superb dashboards and data visualizations it won’t help until the quality of data is high. your ETL scenario won’t be so much great when there are more than one source for the same data but with different versions of it.
Data Governance and Enterprise Information Management (EIM) are concepts that needs to be covered in every organization working with the data, despite the fact that they use BI system or not. So in nutshell EIM and Data Governance are not components of BI system, they are separate systems, that can be used side by side of a BI system. However because of their very close relationship with BI system (especially because BI system is based on the data and information) we would cover them here. I would like to comment here that there won’t be a good BI system without good EIM or data governance in place.