Zara employs the most well known example of supply-chain strategy: Just-In-Time. I'll answer what Just-In-Time is in a bit. But first some history.
Most fashion houses have separate locations for design and manufacturing, usually separated by thousands of miles. Stuff that is sold in GAP stores in the USA are mainly manufactured in Indonesia, China, and Vietnam. These orders are usually placed in huge bulks to save in manufacturing costs and give time to slow sea transportation to sail.
This is the case because most brands have a specific theme that is relatively unique to their company. When you walk into an Abercrombie & Fitch store, you already know what their clothes will generally look like. The same applies to Gucci, LV, Marc by Marc Jacobs, and most other brands. This means these companies are not interested in "chasing the trend" but in creating or maintaining the trend. They have a very specific look that has evolved to their signature look.
Therefore, these fashion companies generally design their entire line up for the following year/season before handing it to manufacturing. It makes sense for them to consider how each one of their designs fit into a bigger theme of style. Pretty much everyone knows that an Abercrombie & Fitch jacket is going to have a vanilla/cream outer color, and huge embroidered words spelling out the brand, with the usual fluffy layer inside.
Hence, their supply chain looks like this:
Design entire line > Forecast > Manufacture in bulk > Logistics
There is no urgency to speed up the supply chain for any reason at all.
Zara on the other hand, is in a market segment called "Fast fashion", which means it emphasizes the transition between couture and catwalk fashion to ready-to-wear. Therefore, the strategic focus boils down to two factors, speed and price.
The faster a company can put new trends into stores, the greater first move advantage they have, and the cheaper they can do it, the larger their margins. Hence, these brands typically operate with very capable and active management and technological support.
Hence their supply chain looks like this: