A backlog is every customer order that has been received as an order that has not yet fulfilled the customers request.

  This type of work activity does not meet the criteria of value added work, mainly because a customer is not willing to pay for the product, service, activity or information.  However, the product, service, activity or information although not considered value added is necessary to either protect the company or comply with regulatory requirements. Because of this it must be performed by the organization.  This type of work is still considered wasteful.

Tip:
  Although business necessary work can not always be eliminated right away these activities should still be reduced or minimized as much as possible until they can be removed.