Does a flooring material have an absolute value of slip resistance?

No, different methods of testing produce different test results. The UKSRG recommends the use of the pendulum to assess the risk of pedestrian slips.
The performance of a floor will change over its lifespan depending on wear and cleaning/contamination.
Wear characteristics of a flooring material can be assessed by use of an accelerated wear machine.
The footwear worn by the people using the floor will affect the friction in the system.