Your manufacturing company's lifeblood is often focused strongly on supply chain management. Imagine going through a drive-thru at a fast food restaurant and having the server tell you that a particular food was backordered and wouldn't be available for many weeks. Not only would that sale probably be lost, but future business would be placed in peril due to the long wait. This type of interaction would impact your trust in that company to deliver what they promised in a timely manner. Next time you drive through the area, you'd probably frequent a different establishment for your needs.
With situations such as those mentioned above, it's no surprise that poor manufacturing inventory management processes can be among the main reasons why these types of businesses fail.