Services can't be counted intuitively.
However, services are an important part of a supplier's value
Technical Indicators
For highly technical industries, suppliers add value because they have unique technology.
Asset Management
Supply management directly affects a company's asset management, such as inventory turnover, cash flow.
People and Process
Process management is the optimization of business processes related to suppliers, such as forecasting, replenishment, planning, contracting, inventory control, information communication, etc.