In service-dominant logic, we see value differently to the traditional approach (where value is set by manufacturer and measured by the price paid - value-in-exchange). We see a beneficiary who is seeking to make progress in some aspect of their life. And they are hiring a service that proposes to help them make that progress.
Value is therefore only measurable by the beneficiary, and measures the amount of progress the beneficiary feel they have made
This measure is complicated by the baggage the beneficiary brings to the service - there lived experience. As well as the experience they have during the service provision - context, their mood, servicescape etc. Both this lived and living experience are phenomenological
We could interpret this foundational premise as the more approachable: Value is always uniquely determined by the beneficiary based on their lived and living experience