I have not seen hard and fast rules for the number of continuous improvement personnel per # of employees. Each organization has its own structure. In hospitality they generally had a number of hotels share a Black Belt, but made sure all employees had Green Belt Training. Many companies dedicate the bulk of their continuous improvement personnel to processes within operations. I’ve seen Call Centers that had a small trained Lean Six Sigma staff who depended on customer service representatives to get involved in projects that didn’t require IT involvement. It depends.