Wash. Rev. Code § 7.70A.050
(1) An arbitration under this chapter shall be conducted according to the time frames specified in this section. The time frames provided in this section run from the date all defendants have agreed to arbitration in their answers where the parties elected arbitration in the initial complaint and answer, and from the date of the execution of the stipulation where the parties agreed to enter into arbitration after the commencement of the action through a stipulation filed with the court. The arbitrator shall issue a case scheduling order in every case specifying the dates by which the requirements of (b) through (f) of this subsection must be completed.
[ 2006 c 8 s 309.]