Unless the Bureau upon motion, for the convenience of parties and witnesses and in the interest of justice, orders otherwise, methods of discovery may be used regardless of sequence, and the fact that a party is conducting discovery, whether by deposition or otherwise, does not operate to delay another party's discovery.
55 Pa. Code § 41.121
This section cited in 55 Pa. Code § 41.92 (relating to expedited disposition procedure for certain appeals); 55 Pa. Code § 41.111 (relating to disclosures); and 55 Pa. Code § 41.134 (relating to discovery motions).