Do I need a consulting service to implement data governance solution like Microsoft Purview?

Argha Banerjee 

As someone that does the consulting you're asking about, when we get asked about what the internal role looks like for this, it needs to be someone, or a small group of someones, dedicated to implementing your information protection and governance solutions. Only the internal team can determine if you have the staff and availability to complete this, or if you would need to open up some roles to do so, which has it's own set of costs in itself. However, this journey is not one that should be done as a "side" portion to an existing role. Not in an enterprise landscape. 

There are routes to do this without consulting but there are also valid reasons to get the consulting. But it will be a journey and you should consider that when picking your consulting partner.

The implementation depends on the beginning work. If you take the time to properly discover and know your data landscape, if you take the time to design your policies on paper first, if you work with the different business units to understand what data they're handling and their use cases (both valid and not valid), if you do the leg work to understand which applications or service domains or browsers you trust to handle sensitive data, if you build your classification tiers (sensitivity labels) in a way that your users will understand and can follow, your implementation can be extremely smooth. But if you don't do the leg work first, it will likely lead to multiple issues and negative user experiences.