Covid-19 management tool

Did your country used, during the COVID-19 pandemic, a specific tool to determine the level of severity of the pandemic, at national level (e.g., level 1, level 2, level3)?  

If yes,

• was this tool linked to public health measures (e.g. different testing, isolation, quarantine, mask wearing, …, measures depending on the level) ?
• what were the different indicators included in that tool?
• is this tool still applicable today? Why?