Ask in your organization who is responsible for product master data. And then ask someone else. You will probably find out that there are several viewpoints in your organization depending on the role and tasks. The biggest challenges found in this are ownership and sharing the product master data in the organization. The whole organization depends on product master data: production, quality (QA and QC), marketing, Innovation/R&D, legal, planners, purchasing, delivery, and many more.
If you want a better grip on product master data (after you defined what master data is) you need to find out who generates master data in what step of what process. Then which solutions are used (like excel) to manage the product master data.
Often multiple solutions are used to manage product master data. Which one is the master? The others should be slaves. The master is the solution that creates and updates the data and makes them obsolete.