Object dependencies in Routings

I have a relatively simple requirement for a configured product:

If option A is picked read a time from a variant table and add it to the existing routing time.

I am able to set the standard value in the routing using this format: $self.std_val3 = time1, but what I want is to add time1 to the existing standard value: Something like this: $self.std_val3 = $self.std_val3 + time1, but this doesnu2019t work.

A second related problem is reading time1 from the table. If I assign the dependency to the configuration profile I can read time1 using this:

table opt1

(opt1 = $root.opt1,

time1 = $self.time1)

If I assign this dependency to the routing operation I am not getting anything for the time.

Thanks

Tom