What is the limitation on time limits in collective agreements?

Time limits in collective agreements are meant to be respected by the parties and should be extended only in exceptional circumstances. Those circumstances always depend on the facts of each case; see Salain v. Canada Revenue Agency, 2010 PSLRB 117. I agree that the criteria are not fixed and are not of equal weight and importance (see IBEW and Gill). However, I cannot agree with the bargaining agent in this case that the first criteria can be ignored completely. There must be a clear, cogent, and compelling reason for the delay filing a grievance. The grievance system is designed to be an effective and efficient way of dealing with disputes in the workplace. Time limits should be generally respected and should be extended only when there are compelling reasons.