I've been using the solution for seven years. It's been a while. 

I have been using Knowage for about two or three years.

I've used the solution for three years now. It's been a while. 

I have used it for six months, in a project for the Italian Department of Health and Human Services ("Ministero della Salute").

I have used SpagoBI for three months.

We have been using SpagoBI for one year.

4 years.

We have used it for at least a year and will continue to do so.

I have used it for two years.

I have been using SpagoBI suite since Version 3.6. Right now, I'm using Version 5.1.

Three years using SpagoBI v4.2, v5, v5.2 and Knowage.

I used it for 2.5 years.

Six months

We have been using this solution for nine months

3 years, from version 4.0 to version 5