Q: How much extra zipper should I order for replenishment?
How much extra to order for replenishment depends on the failure rate, the lead time and the cost of a shortfall. A common approach is to add a small percentage to the production quantity, often in the region of two to five percent for a stable style, and more for a new style or a construction with a known weak point. The extra covers sampling, damage in the wash or the sewing room, and replacement of defective pieces without a new production run. Ask whether the extra can be produced in the same tape lot, because a top-up from a new lot may not match. For long programmes, it is often better to hold a stock of finished zippers than to rely on a fast reorder. Compare the carrying cost with the cost of air freight for an emergency top-up. Record the spare quantity and its lot number so it can be used deliberately rather than discovered at the end of the season.