The rules are designed to ensure a fair and consistent application of due process (in the U.S.) or fundamental justice (in other common law countries) to all cases that come before a court.
[2] The standardization for the means by which cases are brought, parties are informed, evidence is presented, and facts are determined is intended to maximize the fairness of any proceeding.
For example, they impose specific time limitations upon the parties that may either hasten or (more frequently) slow down the pace of proceedings.
Legal procedure, in a larger sense, is also designed to affect the best distribution of judicial resources.
Even the scientific handling of law, which developed during medieval times in the new universities in Italy (in particular in Bologna, Mantua), did not come to a full and clear separation.
The English system of "writs" in the Middle Ages had a similar problem to the Roman tradition with the actio.
In Germany, the unity of procedure and substance in the actio definitely was brought to an end with the codification of the Bürgerliches Gesetzbuch (BGB) which came into force on January 1, 1900.