The inherent value of a product in the eyes of the customer, reflected by its selling price and market demand.
In most products, value is created by a combination of actions by the producer, some of which produce value in the eyes of the customer and some of which are simply necessary given the current configuration of the design and production process. The goal of 'Lean Thinking' is to eliminate the second group of activities and maintain or improve the first group.
Any activity that is valuable in the eyes of the customer. A simple test to find out whether an activity and the time required for it are value-creating is to ask
whether the customer would consider a product less valuable if this activity could be omitted without affecting the product. For example, repair work and waiting time will not be readily identified as valuable by customers, but design and manufacturing steps will be.
Any activity that, in the eyes of the customer, adds cost but not value to a product or service.