Because of the massive number of peripheral parts involved, umbrella production must be situated in a collaborative stream of factories, with raw material suppliers "upstream," and parts manufacturers "downstream."
也因為周邊配件眾多，因此製傘也是一種講求群聚的事業，所有的製傘商都必須跟著上游原料廠商、下游零配件廠商的腳步走，無法單打獨鬥。