先看一段Gartner对于TCO的定义
Gartner defines total cost of ownership (TCO) a comprehensive assessment of information technology (IT) or other costs across enterprise boundaries over time. For IT, TCO includes hardware and software acquisition, management and support, communications, end-user expenses and the opportunity cost of downtime, training and other productivity losses.
试想一下，如果我们采购服务器的渠道被掐断，那么就只能通过不断提升现有机器的利用率，才能应对日益扩大的业务规模。
wiki描述
Technology deployment can include the following as part of TCO:
- Computer hardware and programs
- Network hardware and software
- Server hardware and software
- Workstation hardware and software
- Installation and integration of hardware and software
- Purchasing research
- Warranties and licenses
- License tracking - compliance
- Migration expenses
- Risks: susceptibility to vulnerabilities, availability of upgrades, patches and future licensing policies, etc.
- Operation expenses
- Infrastructure (floor space)
- Electricity (for related equipment, cooling, backup power)
- Testing costs
- Downtime, outage and failure expenses
- Diminished performance (i.e. users having to wait, diminished money-making ability)
- Security (including breaches, loss of reputation, recovery and prevention)
- Backup and recovery process
- Technology training
- Audit (internal and external)
- Insurance
- Information technology personnel
- Corporate management time
- Long term expenses
- Replacement
- Future upgrade or scalability expenses
- Decommissioning