NCSC Cyber Exercise In A Box

Exercise in a Box is an online tool from the National Cyber Security Centre (NCSC) which helps organisations test and practise their response to a cyber attack. It is completely free and you don’t have to be an expert to use it.

Cyber exercising can help you understand your organisation's preparedness and resilience to cyber attacks. This service covers the fundamentals of cyber exercising which helps you to find out how resilient your organisation is to a cyber attack, and to practise your response to critical cyber incidents in a safe environment. 
https://exerciseinabox.service.ncsc.gov.uk/