I watched a video of Jarrod Goenzel, Director MIT Humanitarian Response Lab. The link is here: http://bit.ly/1bDLro0. Early on in the video, Jarrod Goenzel talks about one of the major supply chain / logistics problems in humanitarian logistics being that there is no demand information, not only the amount to be shipped but even what to ship.
When you know demand you can formulate a plan for the volume of goods being moved on an efficient basis. In a humanitarian crisis there may be no direct method of getting demand.
In business, there are times demand is not known, such as situations where there is new business or a new product. Occasionally item with a small demand becomes a fad item and demand sky rockets.
In the humanitarian crisis, demand can be determined from past experience and by viewing social media messages from the area of demand. Procedures can be put place to estimate demand to start the planning and execution process.
In business, demand for new products may be estimated using market surveys or even flat out guesses. Once shipments begin, the demand forecast will need to be revised from actual sales but possibly also information such as social media.
The key to success, success being defined as meeting customer expectations in an efficient operation, is using revised demand forecasts to change your supply chain / logistics plan.