What is the test for an administrative tribunal’s ability to set its own rules?

As stated by Mr. Justice Sopinka in Prassad v. Canada (Minister of Employment and Immigration), 1989 CanLII 131 (SCC), [1989] 1 S.C.R. 560, [1989] S.C.J. No. 25 at paragraph 16: “16. We are dealing here with the powers of an administrative tribunal in relation to its procedures. As a general rule, these tribunals are considered to be masters in their own house. In the absence of specific rules laid down by statute or regulation, they control their own procedures subject to the proviso that they comply with the rules of fairness and, where they exercise judicial or quasi-judicial functions, the rules of natural justice.”