Build a relevant cross-functional team; team members have to be selected based on their experience and knowledge: an Operator, a Production Supervisor, Process / Manufacturing Engineers. APU, EngDescribe the problem (When, Why, What, Who, How many, Where & How) to ensure the customer complaint is fully understood. Use data such as Pareto charts, process flow charts, histograms, measurement reports, pictures, and get the defective parts from customer.