Companies collect a wide variety of data, from multiple sources. This information can be collected internally or from customers, or even captured from the web and social networks. However, during this process, different problems can arise. First of all, a dataset can contain duplicate data, i.e. several identical records.Data can also conflict. A dataset may contain several similar records with different attributes. On the contrary, sometimes data attributes are missing. The data may also not be compliant with regulations.