To top managers at Levi Strauss, revamping the information technology system seemed like a good idea. The company had come a long way since its founding in the 19th century by a German-born dry-goods salesman: In 2003 it was a global corporation, with operations in more than 110 countries. But its IT network was antiquated, a balkanized mix of incompatible country-specific computer systems. So executives decided to migrate to a single SAP system and hired a team of Deloitte consultants to lead the effort. The risks seemed small: The proposed budget was less than $5 million. But very quickly all hell broke loose. One major customer, Walmart, required that the system interface with its supply chain management system, creating additional hurdles. Insufficient procedures for financial reporting and internal controls nearly forced Levi Strauss to restate quarterly and annual results. During the switchover, it was unable to fill orders and had to close its three U.S. distribution centers for a week. In the second quarter of 2008, the company took a $192.5 million charge against earnings to compensate for the botched project—and its chief information officer, David Bergen, was forced to resign.

A version of this article appeared in the September 2011 issue of Harvard Business Review.