The post points out that competing a "demand" needs to factor-in the delivery date (requested) vs the shipped date (realized). However, I am afraid, this is a very thin contribution.

Demand is an incredibly multi-faceted topic. Demand is never observed. Only sales, or sales intents are observed. The sales are conditioned by many (many) factors that distort the perception of the demand.

First, let's start with the easy ones, the factors that simply censor your perception of the demand:

• No having the right product to sell. The sales never happen, yet, demand was there.
• Not having the right price. Idem, demand exists, just not for this price.
• Not having the right position (bad image, bad description). Visitors miss what they could have wanted.
• Not having the right delivery promise. Visitors give up if out-of-stock or if delivery date is too far away.

Then, we have all the big factors:

• Say's law: Supply creates its own demand, demand isn't prexisting, it's engineered as such.
• Branding: take two physically identically product plus/minus the brand, demand changes entirely.
• Cannibalizations and substitutions: demand covers a whole spectrum of willingness to buy. Demand cannot be understood at the product level.
• etc

Looking at the demand through the lenses of time-series analysis is short-sighted.

Ps: thanks a lot for being one of the first SCN contributors!