Most are familiar with the notion of supply chains, and describe them as assembling product, of some type, and moving it through a series of points where it often receives further investment in packaging and processing, to a customer of consumer.
Similarly, the concept of value chains is familiar, the emphasis being on the addition of the perceived value (usually again, packaging and the changing of the product form) at each point in the chain.
The notion of a demand chain changes the perspective of the chain 180 degrees, and seeks to define the whole chain in the terms of the end user, and what adds value to them. If some activity, or investment in the product does not add value to the end consumer of the product, why do it?
Most businesses, particularly in the agricultural sector where the food industry has its roots, produce stuff, and do it as well as they can, then look for someone to buy it, often an intermediary of some sort. This process repeats itself at each point in the chain.
How much better to start with the consumer, define their needs, and translate them back through the chain, with each point focussing on the end consumer as the reason to do, or not do, something. Voila, a demand chain!