The value grid model was proposed by Pil and Holweg as a means to show that the way firms compete has shifted away from the linear value chain way management theory has traditionally thought about value chain management.
The advantages of a value-grid framework, as opposed to value chains, is in allowing companies' managers to strategize and coordinate operations. Common non-linear value chain strategies include influencing demand, modifying information access, exploring multitier penetration, managing risk, seizing value, integrating value, creating new value propositions, exploiting value chains across tiers, pursuing pinch-point mapping, and defining demand enablers.
Literature
Pil, F.K. and Holweg, M. (2006) "Evolving from value chain to value grid." MIT Sloan Management Review, 47(4): 72-80