HBS Working Knowledge offers an article on IT Investments that Pay Off:

Our research revealed, in particular, that three practices distinguish the companies that were most successful in their IT investments. First, such companies targeted their investments at the productivity levers that mattered most for their industries and themselves. Second, they carefully thought through the sequence and timing of their investments. Third, they didn't pursue IT in isolation but rather developed managerial innovations in tandem with technological ones. Let's look more closely at how these imperatives drive productivity.