Multiplicity of Proceedings. SS & C Technologies Canada Corp. v. The Bank of New York Mellon Corporation
In SS & C Technologies Canada Corp. v. The Bank of New York Mellon Corporation (Ont CA, 2021) the Court of Appeal considered whether an appeal on the liability portion of a trial should proceed before the damages trial had been completed. Normally, appeal courts want to have all the issues before them to avoid a 'multiplicity of proceedings' [CJA 138]:
 Section 138 of the Courts of Justice Act, R.S.O. 1990, c. C.43 (“CJA”), makes clear that “[a]s far as possible, multiplicity of legal proceedings shall be avoided”; see also Vaeth v. North American Palladium Ltd., 2016 ONSC 5015, at para. 37. This court held in Elcano Acceptance Ltd. v. Richmond, Richmond, Stambler & Mills (1986), 1986 CanLII 2591 (ON CA), 55 O.R. (2d) 56 (C.A.), at p. 5, that the power to split a proceeding “must be regarded as a narrowly circumscribed power.”
 Courts generally seek to avoid a multiplicity of proceedings and the potential of inconsistent results. One appeal dealing with all issues is ordinarily the most effective and fair use of both public and private resources: Korea Data Systems (USA) Inc. v. Aamazing Technologies Inc., 2012 ONCA 756, 29 C.P.C. (7th) 51, at paras. 23-25.
 This is particularly true when there is a real possibility that one or both parties may bring further appeals of the application judge’s decision: Toronto (City) v. 1291547 Ontario Inc. (2001), 2001 CanLII 7244 (ON CA), 148 O.A.C. 212 (C.A.), at para. 13.
 In Toronto (City), the respondent moved to adjourn the trial for damages until its appeal on the trial judge’s finding of liability had been heard. This court held, at para. 13, that the balance of convenience supported the completion of the adjudication of all the issues in the Superior Court of Justice, as then both the liability and damages issues could be dealt with in one appeal.
 In Korea Data Systems, this court heard an appeal of a liability decision, while a hearing on damages and other outstanding issues was scheduled concurrently by the court of first instance. This court held that the “interests of justice” favoured staying the appeal to allow the damages hearing to be completed first, as this approach “avoids a multiplicity of proceedings and the potential of inconsistent results”: Korea Data Systems, at para. 23. Notwithstanding that the issues on appeal were serious, the issues were separate and discrete from those remaining to be determined at first instance, and little prejudice would result in allowing the appeal to proceed, this court held that the overall interests of justice favoured the disposition of all issues before hearing the appeal: Korea Data Systems, at paras. 23-25.
 In Canadian Planning and Design Consultants Inc. v. Libya, 2015 ONCA 661, 390 D.L.R. (4th) 267, this court held, at para. 53, that “[i]t is not an efficient or appropriate use of judicial resources to have two different courts determining the merits of the same issues in what is essentially the same litigation, especially where multiple appeals to this court may result”. The concerns of judicial economy and avoiding the risk of inconsistent rulings were held to favour adjourning the appeal pending resolution of a motion in the Superior Court of Justice: Libya, at para. 53.
 Where the only harm the appellants might be exposed to is the expense they would incur if the trial went ahead before the appeal and this court on appeal determines that there was no proved breach, the harm suffered by the appellants can be taken into account in costs or damages: Toronto (City), at para. 11.
 As noted in the cases cited above, the ordinary practice is to pursue a single appeal from decisions on liability and damages. The moving party must establish that it is in the interests of justice to do otherwise. Fragmenting appeals, particularly in large and complex cases such as this, may well delay the overall administration of justice at both the trial and appeal court level by having appeals of different aspects of the case heard at different times.
 I recognize that the appellants have raised serious issues in their appeal of the Liability decision and, if successful, the appeal may dispose of some or all of the claims. However, if the Liability appeal is scheduled now, there will be a multiplicity of proceedings being heard and resolved concurrently.