Most of our clients visit their vendors at least once a year (scope re-baselining/ annual planning). More proactive ones make at least 1 additional visits spread 6 month from the earlier visit. Second visit is more focused around operational or capability issues. Here the other client team members accompany the vendor relationship managers (ADM, testing etc).  At times there is single visit but meeting is split by tracks. This all depends upon the years of relationship with vendor.

In earlier phase of relationship we recommend one visit every 6 months. Also we recommend to include a few new members (who were not directly involved in vendor selection process), as this gives them firsthand experience of vendor capabilities.This also gives offshore delivery team an opportunity to showcase their progress and acts as a good bonding experience. Reward and recognition play a big time in this integration.  

Once there is sufficient trust and transparency in partnership annual visits also work very well along with monthly rhythms, relationship scorecards and governance meets.