Value Chains ⇨ Value Networks
In an article 'Value Creation, Coordination and Positioning in Supply Relationships' in Long Range Planning (Volume 39, Issue 2, April 2006, Pages 133-153), Lars Huemer has reservations as to the usefulness of the value chain model and the notion of value systems as general representations of value creation, coordination and positioning in supply relationships.
He suggests that value configuration analysis including the value network logic provides a fruitful alternative, and can reveal a number of complexities in supply relationships, including differences in value creating logic, sets of interdependencies and more compound supply structures.
I agree with him that it's time to say goodbye to Porter's process-oriented, sequential Value Chain model and proceed with the more flexible and interdependent non-sequential collaboration-oriented Value Network models.