International Business Machines Corporation IBM

The business

IBM sells three things to the largest organisations in the world. Software is Red Hat, the automation and data platforms, and the transaction processing stack that runs inside banks and insurers, and it carries roughly a third margin. Consulting is people who show up and integrate it, at roughly a tenth. Infrastructure is the mainframe, which still exists because moving a bank's core off it costs more than replacing the bank.

The three are supposed to feed each other: the mainframe cycle pulls software, the software pulls consulting hours. When it works, the mix improves and the margin follows. When the mainframe cycle turns, all three move at once and in the same direction.