Washington's Administrative Procedure Act (RCW 34.05), particular Part III, Rule-Making Procedures, deals with the development of rules and regulations. The Regulatory Fairness Act (RCW 19.85) deals with the "disproportionate impact" of administrative rules and regulations on small businesses.
The Rule Making process is itself governed by a set of rules (WAC 1-21).
Here is a graphic representation of the regulatory process:
Sometimes a researcher needs to trace the history of a regulation to see how the regulation has changed over time or to determine if the history reveals anything useful about intent.
Gallagher reference librarian Mary Whisner wrote about this process in the Washington Legal Researcher's Deskbook 3d.