Ideally every Key Result is measured using a KPI with a numerical value
However, there are time when the Key Result is more task like and cannot be measured. In these scenarios you can use a Percentage Complete or Milestones Key Result
When creating the Key Result select one of these types

The Percentage Value option allows you to update the progress of the Key Result by entering a percentage between 0 and 100% where 100% means the Key Result has been achieved
The Milestone versions allows you to define the key milestones for achieving the Key Result and assign then percentages to display in the progress

In either case you update the progress using a Key Result menu or drag the progress bar
