Are the people, machines, or processes delivering or supplying products or parts they have made to the next (in sequence) work area(s). Internal Suppliers have an opportunity to satisfy an "Internal Customer" by delivering quality products, on time, every time, where their Internal Customers want them, how they want them, etc. Essentially, everyone and every department is someone's customer and someone's supplier. Departments may have many different Internal Suppliers and Internal Customers. Whether an individual or a department has only one or many customers/suppliers they should always treat them as if they were "prized customers" or "valued suppliers."