IBM's business model has undergone more fundamental reinventions than perhaps any other technology company in history. What began as a manufacturer of tabulating machines and time clocks has transformed through mainframes, PCs, services, and now into a hybrid cloud and AI platform company. The current model, shaped decisively by Arvind Krishna's strategic choices since 2020, is built around four reporting segments that work together to help large enterprises modernize their technology infrastructure without the disruption of wholesale migration. The Software segment is IBM's highest-margin and most strategically important business, generating approximately $26.3 billion in revenue in FY2024 — roughly 42% of total revenue. This segment includes Red Hat (hybrid cloud infrastructure software including OpenShift, Ansible, and RHEL), Data and AI platforms (watsonx, Db2, DataStage), transaction processing software (CICS, IMS, z/OS), automation tools (Turbonomic, Instana, Apptio), and security solutions (QRadar, Guardium). The segment operates at gross margins around 80%, reflecting the economics of enterprise software licensing and subscriptions. Red Hat alone contributes over $7 billion in annual revenue and is growing at double-digit rates, making it the financial engine of IBM's transformation. The Consulting segment generated approximately $20.2 billion in revenue in FY2024, making IBM one of the largest technology consulting firms globally. This business combines traditional IT consulting with implementation services for hybrid cloud migrations, AI deployments, and digital transformations. IBM Consulting competes with Accenture, Deloitte, and the other Big Four consulting practices, differentiating primarily through deep expertise in regulated industries (banking, healthcare, government) and proprietary IBM technology integration. Gross margins in consulting hover around 27-29%, lower than software but providing essential customer access and deal flow that feeds software adoption. The Infrastructure segment — approximately $14.3 billion in FY2024 revenue — encompasses IBM's mainframe business (z16 and successor systems), Power servers, and storage systems. This is the legacy business that many analysts misunderstand. IBM mainframes process roughly 87% of global credit card transactions, handle trillions of dollars in daily financial transfers, and run core systems for airlines, insurers, and government agencies that cannot afford downtime. The mainframe business operates on a cyclical refresh model (roughly every 2-3 years for new generations), with each cycle generating hardware revenue followed by years of high-margin software and maintenance revenue. It's not growing in unit terms, but it generates extraordinary cash flow. The Financing segment (approximately $800 million in revenue) provides credit and financing solutions to clients purchasing IBM hardware and software, functioning essentially as a captive finance company that smooths purchase decisions and generates interest income. The strategic logic connecting these segments is what IBM calls the 'hybrid cloud platform' thesis: enterprises will operate in hybrid environments (mixing on-premises, private cloud, and multiple public clouds) for decades to come, and they need software to manage that complexity, consultants to architect transitions, and infrastructure that can participate in hybrid topologies. Every dollar of Red Hat revenue creates consulting opportunities (deployment, migration). Every consulting engagement creates software opportunities (watsonx, automation). Every mainframe modernization creates hybrid cloud opportunities (connecting z/OS workloads to OpenShift). This flywheel is what IBM means when it says its platform has $174 billion in total addressable market. Revenue model: IBM has been transitioning from perpetual licenses and one-time hardware sales toward recurring revenue. Annual Recurring Revenue (ARR) exceeded $14.9 billion in FY2024, growing at approximately 10% year-over-year. The shift toward subscriptions and consumption-based pricing means IBM's revenue base is becoming more predictable, though the transition temporarily pressures top-line growth as large upfront deals convert to smaller annual payments spread over contract life.