What procurement methods does you company use?

I am working in Procurement Department in BI Group, the leading construction company in Kazakhstan. (FYI - our website https://sales.bi-group.org/en-kz) Currently I am searching for the procurement practices that other companies use around the globe. Could you please provide some information on the following questions: 1) What methods does your company use to procure? Via tenders, commercial offers? 2) Are there electronic tenders held? 3) Is there any problems with corruption? If so, what measures do you take to prevent it? 4) Is the ERP system used? Which one? 5) What main procurement insights can you share with?