Thread by @tdpauw

When IT is seen As A Cost Centre it will be incapable of revenue creation.
In this scenario an org has a standalone IT department with annual budget and plan. Focus will be on maximising resource utilisation by keeping people busy and minimising cost by outsourcing.

When IT is seen As A Business Differentiator it is a direct or indirect revenue creator.
In this scenario an org has its IT department integrated into its business vertical with rolling budget and plan. Focus will be on optimising flow of work and limiting work in progress.

When an org has an IT As A Cost Centre, its reliability strategy will be to Optimise For Robustness by prioritising a higher Mean Time Between Failure (MTBF) over a lower Mean Time To Repair (MTTR).
-- Measuring Continuous Delivery @SteveSmithCD

In an IT As A Cost Centre org the production environment is seen as a failure-free place, in which services have predictable interactions in repeatable conditions.
Failures are believed to be caused by isolated, faulty changes therefore are considered preventable.

Usually in an IT As A Cost Centre robustness is achieved by relying on the following risk management practices:
- end-to-end testing
- change advisory boards
- change freezes
- manual regression testing
- segregation of duties

Optimising For Robustness requires too much time for too little risk reduction:
- end-to-end testing: test coverage will be low
- change advisory boards: deployments can still fail
- change freezes: production failures still occur
And all increase lead time and opportunity costs