The document discusses continual service improvement (CSI) as presented in ITIL. CSI aims to continually align IT services with changing business needs through identifying and implementing improvements across the service lifecycle. This includes determining appropriate metrics, setting goals and targets, and reviewing results to ensure quality. CSI provides benefits such as enabling continuous feedback, calculating returns on investment, and validating monitoring activities. Supporting models discussed include PDCA (plan-do-check-act) and a 7-step improvement process.