Value stream mapping is actually a visualization tool to map the path and hence identify all the activities involved in the product or service. All of the activities of a product or service are mapped on a paper using flowcharts. This helps in identifying and eliminating non-value added activities.
Non-value adding activity is any activity that does not add any value to the product as perceived by the customer. Value adding activity, on the other hand, adds value in the making of a product, which in overall adds value to the customer who is using the final product.
For any product or service, it is necessary to define value. For someone flying from New York to London, the value is in reaching England safely along with his baggage. Activities like, waiting for the pick-up cab, putting the baggage in the cab, getting boarding pass at the check-in counter or waiting at the immigration, are all examples of non value adding activity to this person.
Any activity of a value stream map can be classified into three groups. First, activities that add value as perceived by the customer. Second, activities that add no value but are required by the process and finally activities that add no value and can be eliminated.