A known error is a problem that has been analysed but not resolved1. This means that the root cause of the problem has been identified, but a permanent solution has not been implemented yet2. A known error can be recorded in a known error database (KEDB) and linked to related incidents and problems3. References: ITIL Foundation - ITIL 4 Edition, page 15; ITIL 4 - A Pocket Guide, page 35; ITIL 4 Practice Guide: Problem Management, page 8.

Continual improvement encompasses all elements of the ITIL SVS. It involves aligning an organization's practices and services with changing business needs, through the ongoing assessment and improvement of each element involved in the management of products and services. Continual improvement applies to the SVS in its entirety, as well as to all of the organization's products, services, service components, and relationships, and is the responsibility of every individual involved in service management.
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