Court Opinion

ID: 9531688
Source: CourtListenerOpinion
Date Created: 2023-08-07 04:13:55.058448+00
Date Added: 2024-06-11T13:28:33.991587
License: Public Domain

Boyle, J.
(concurring). In Pike v City of Wyoming, 431 Mich 589; 433 NW2d 768 (1988), a majority of this Court held that despite a prior, final award of benefits by the bureau, the doctrine of res judicata did not preclude the defendants from relitigating the issue of the plaintiffs wife’s dependency. It was my expressed view in Pike that the majority of this Court had based its decision, not upon the law of res judicata, but upon an ad hoc notion of public policy. In my dissent in Pike, I explained:
There may be matters of public policy so extraordinary as to justify a departure from res judicata principles. However, a court’s vague notion of "fairness” — though motivated by benevolence in a particular case — does not justify the substantial injustice that results when finally decided cases are reopened. Such a view negates the expectations of the bar on which client advice is predicated and corrupts the decision-making process of a court. [Pike, supra, pp 630-631 (Boyle, J., dissenting).]
Today, a majority of this Court takes one step beyond Pike, abandoning both law and public policy as a basis for its decision. The majority prefaces its holding as follows:
*727Neither general res judicata doctrine nor policy requires one result in preference to the other. [Ante, pp 720-721.]
I agree with the majority that the doctrine of res judicata does not preclude1 the plaintiff from litigating his 1973 change of condition. However, contrary to the majority, I believe that both the principles of res judicata and sound public policy require this result.
i
Recent deviations from the rule of res judicata notwithstanding,2 Michigan does follow the broad rule of res judicata with regard to workers’ compensation claims. Gose v Monroe Auto Equip Co, 409 Mich 147; 294 NW2d 165 (1980). Under this rule:
When a valid and final judgment rendered in an action extinguishes the plaintiff’s claim pursuant to the rules of merger or bar . . ., the claim extinguished includes all rights of the plaintiff to remedies against the defendant with respect to all or any part of the transaction, or series of connected transactions, out of which the action arose. [1 Restatement Judgments, 2d, § 24(1), p 196.]_
*728Thus, the Restatement formulation of the rule of res judicata focuses upon the transaction out of which the action arose and designates the date of a "final judgment” as that upon which res judicata attaches to the claim.
The initial error of the majority is the assumption that a rule of res judicata may simply be grafted onto the decision of choice. The majority reasons:
In neither Gose nor Hlady [v Wolverine Bolt Co, 393 Mich 368; 224 NW2d 856 (1975)], however, did this Court focus on the question now presented, whether the "time” of the award for res judicata purposes is the date of the decision by the referee or the date of the decision by the wcab where an intervening change in physical condition may, as recognized in the passage from Hlady quoted in Gose, justify a further award of benefits or the stopping of payment on an award previously entered. [Ante, pp 719-720.]
While it is literally true that neither of these decisions sets forth the "time” at which res judicata attaches, the reason is that it is not the time, but the state of finality which determines whether res judicata is applicable. Thus, the Hlady majority explained:
"Where issues of fact or law have been finally decided by a court of competent jurisdiction in one legal action which are essential to the maintenance of another legal action, it is universally held that the second action must fail.” [Hlady, supra, p 376 (emphasis added), quoting with approval Jones v Chambers, 353 Mich 674; 91 NW2d 889 (1958). See also Cohen v Home Life Ins, 273 Mich 469, 473; 263 NW 857 (1935); 1 Restatement Judgments, 2d, § 13, p 132.]
The Workers’ Disability Compensation Act specifies that a claim of appeal may be taken from *729either the decision of the hearing referee3 or the appeal board.4 At the expiration of an appeal period, the decision is final, Abbott v Saginaw Ice & Coal Co, 284 Mich 462, 475; 280 NW 21 (1938), and may be enforced in circuit court. MCL 418.863; MSA 17.237(863).
Here, the hearing referee’s decision awarded a closed period of wage-loss compensation to the plaintiff on December 6, 1972. The plaintiff filed a timely claim of appeal with the appeal board. On October 28, 1974, the appeal board affirmed the decision of the hearing referee. No appeal was taken from the appeal board’s decision. Instead, on March 23, 1977, more than two years later, the plaintiff filed a new claim for wage-loss compensation with the bureau. Her new petition alleged a change of condition which preceded the appeal board’s decision by nearly two years.5
The only final decision in this matter is that of the appeal board dated October 28, 1974. I agree generally with the Court of Appeals conclusion that ”the doctrine of res judicata bars a claim *730which a plaintiff in a workers’ compensation case could have brought, but did not.”6 To be more precise, however, there is but one "claim” which arises from a single transaction or occurrence, although it may be based upon a number of different theories.7 Thus, if in reality there is but one claim involved in this appeal, that alleged in the plaintiff’s second petition is merged with her first and precluded under the general rule of res judicata.
In essence, there are two aspects to the question presented by Jessie Askew’s delayed petition for further wage-loss compensation on the basis of a change of condition. The first question is whether the delayed petition is based upon the same claim as that underlying the plaintiff’s first petition and *731thereby extinguished under the doctrine of merger. See 1 Restatement Judgments, 2d, §§ 18(1), 24, pp 151-152, 196. The second question is whether, assuming that there is but one claim, any exception to the rule of res judicata is applicable. See, generally, 1 Restatement Judgments, 2d, § 26, pp 233-234. In neither question is the "time” of the final decision determinative. In both, orthodox principles of res judicata may be applied to reach a just and practical resolution of this dispute.
ii
That resolution of this matter should turn initially upon what constitutes a "claim” in workers’ compensation proceedings is not surprising. It was essentially this issue which divided the majority from the concurring opinion of Justice Levin in Hlady and the majority from Justice Levin’s dissent in Gose. It is unfortunate that the question was not forthrightly addressed in Hlady and Gose, since the resulting confusion has generated the pluralities of Pike, supra, and Riley v Northland Geriatric Center, 431 Mich 632; 433 NW2d 787 (1988). Nevertheless, this question is not particularly difficult to resolve once it has been recognized.
Under the modern rule of res judicata, what constitutes a "claim” is determined by reference to the transaction or occurrence out of which the injury arose.8 As explained in 1 Restatement Judgments, 2d, § 24(2), p 196:
What factual grouping constitutes a "transaction,” and what groupings constitute a "series,” are to be determined pragmatically, giving weight *732to such considerations as whether the facts are related in time, space, origin, or motivation, whether they form a convenient trial unit, and whether their treatment as a unit conforms to the parties’ expectations or business understanding or usage.
The plaintiff’s claim in this instance is for disability, or wage-loss compensation.9 Thus, if the "transaction” out of which plaintiff’s claim arose is his disability, it would follow that plaintiff’s second claim arises out of a distinct transaction or occurrence. However, upon further reflection I do not believe that there are two "transactions” or claims in this instance.
As explained further in 1 Restatement Judgments, 2d, § 24, comment b, p 199:
In general, the expression connotes a natural grouping or common nucleus of operative facts. Among the factors relevant to a determination whether the facts are so woven together as to constitute a single claim are their relatedness in time, space, origin, or motivation, and whether, taken together, they form a convenient unit for trial purposes. Though no single factor is determinative, the relevance of trial convenience makes it appropriate to ask how far the witnesses or proofs in the second action would tend to overlap the witnesses or proofs relevant to the first. If there is a substantial overlap, the second action should ordinarily be held precluded. But the opposite does not hold true; even when there is not a substantial overlap, the second action may be precluded if it stems from the same transaction or series.
Here, there is a substantial overlap of witnesses *733and other proofs. Indeed, it is in the nature of a petition for compensation based upon a change of condition that the most probative testimony will be that of experts who have examined the claimant both prior to and after the petition for a change of condition. This follows from the long-established rule that, although wage-loss compensation is paid for a limitation of "wage earning capacity,”10 the only issue in a petition based upon a change of condition is the physical condition of the injured worker. See Hood v Wyandotte Oil & Fat Co, 272 Mich 190; 261 NW 295 (1935); White v Michigan Consolidated Gas Co, 352 Mich 201, 210; 89 NW2d 439 (1958) (White II). See also 3 Larson, Workmen’s Compensation, §81.00, p 15-528 (on a reopening for change of condition, no other issues may be relitigated, and the claimant’s evidence must bear directly upon the comparison between his former and present disability).
There also can be little dispute that, if the initial appeal board had been allowed access to the testimony upon which plaintiff’s second petition was based, the sum total would have been a more convenient package for resolution of the factual questions presented by both petitions.11 The common factual issues underlying both petitions are predominant. The appeal board must, for instance, have an understanding of the nature of the injury, as well as the medical testimony presented at the initial hearing.
Naturally, there will not be a complete identity of factual issues underlying both petitions. The *734underlying factual issues of entitlement12 need not be revisited.13 Similarly, when the issue is simply wage-loss compensation, factual issues surrounding medical, rehabilitation, and specific-loss benefits may be irrelevant.14 However, it seems to me an inescapable conclusion that these petitions present a substantial overlap of witnesses and proofs and further that a petition based upon a change of condition arises out of the same transaction or occurrence as the original petition. I would therefore conclude that, under the general rule of res judicata, there is but one claim involved in both petitions. Thus, to my mind, the dispositive question involved in the appeal is whether Jessie Askew’s second petition for compensation falls under any recognized exception to the doctrine of merger under the general rule of res judicata.
hi
Among the recognized exceptions to the doctrine of merger are circumstances in which "it is the sense of the [statutory] scheme that the plaintiff should be permitted to split his claim . ...” 1 *735Restatement Judgments, 2d, § 26(d), p 234. It is in this context that I would place the Michigan rule of res judicata regarding workers’ compensation claims:
"[A] compensation award is an adjudication as to the condition of the injured workman at the time it is entered, and conclusive of all matters adjudicable at that time, but it is not an adjudication as to the claimant’s future condition and does not preclude subsequent awards or subsequent modifications of the original award upon a showing that the employee’s physical condition has changed.” [Gose, supra, pp 160-161. Citing with approval Hlady v Wolverine Bolt Co, supra, pp 375-376. Emphasis supplied in Hlady.]
I would emphasize that, under the practical analyses of Hlady and Gose, as well as the theoretical analysis of the Restatement of Judgments, 2d, the doctrine of res judicata does apply to workers’ compensation proceedings, although it is subject to the long-established exception for a change of physical condition.
In my view, we must be constantly aware of and faithful to the legislative purpose in creating the workers’ compensation remedy. In the context of a much earlier res judicata challenge to a change of condition, this Court explained:
Obviously, plaintiff had no cause of action against his employer in the sense of the common law, or any amendment thereto, to split. Proceedings under the workmen’s compensation act have nothing to do with common-law actions for damages for negligence on the part of the employer. Its enactment marked the crystallization into a legislative enactment of the economic fact that the ultimate consumer pays for the compensation of injured employees in the increased cost of the *736product. It aims at compensation, not damages. It is wholly substitutional in character and displaces the common-law liability for negligence. It should be administered substantially as insurance of a social character. Claimant had no action in law or in equity against his employer. Proceedings under the workmen’s compensation act are purely statutory, — administrative, not judicial, — inquisitorial, not contentious, — disposed of, not by litigation and ultimate judgment, but summarily. Most of the difficulties now encountered in the administration of the workmen’s compensation act arise from injudicious attempts, sometimes acquiesced in, to engraft upon the workmen’s compensation act common-law theories at variance with its spirit and intent. [Hebert v Ford Motor Co, 285 Mich 607, 609-610; 281 NW 374 (1938).]
While we must be faithful to legislative purpose and attentive to the statutory scheme underlying workers’ compensation, we must also be aware that the Legislature does not work in a vacuum. The Legislature is presumed to be aware of the existing decisions of the Court, People v Cash, 419 Mich 230, 241; 351 NW2d 822 (1984), Michigan Gas Storage Co v Gregory, 341 Mich 34, 37; 67 NW2d 219 (1954), and matters of procedure fall uniquely within the traditional power and expertise of the judicial branch. See, e.g., St John v Nichols, 331 Mich 148, 158; 49 NW2d 113 (1951). Thus, in fleshing out the skeletal procedures set forth in chapter 8 of the Workers’ Disability Compensation Act, MCL 418.801 et seq.; MSA 17.237(801) et seq., we must also give careful consideration to the long-established, slowly cured, procedural doctrines of the common law. In the language of the Hebert Court, it is "injudicious attempts ... to engraft upon the workmen’s compensation act common-law theories at variance with its spirit and intent” which we must avoid— *737not all attempts to rely upon common-law procedural rules.
Here we are asked to decide whether the plaintiffs petition based on a change of physical condition resulting in a continuing disability is precluded even though the change of condition occurred after the decision of the referee. It is argued by the defendant that the doctrine of merger precludes this petition, even though the issues it raised could not have been raised before the hearing referee because the plaintiff might have raised these issues during her subsequent administrative appeal. If the plaintiff could have presented this claim, I might agree that plaintiffs claim would be barred under the rule of res judicata as set forth in Hlady and Gose. Upon examination of the statute, however, I am entirely unconvinced that plaintiff either could have or should have raised these issues before the appeal board.
As discussed in the majority opinion, the appeal board formerly had statutory authority to allow the taking of "such additional evidence as it in its discretion may allow . . . .” MCL 418.859; MSA 17.237(859). This controlling statutory language has been modified by 1985 PA 103, which provides that "[t]he board may hear the parties, together with such additional evidence as it may allow . . . .” MCL 418.859; MSA 17.237(859). The majority opinion focuses only upon the language of MCL 418.861a(12); MSA 17.237(861a)(12), which applies not to the appeal board, but to its successor, the appellate commission. Under the circumstances, I find it neither necessary nor instructive to speculate as to the scope of the appellate commission’s authority in taking additional testimony. I believe that it is sufficient to note that the Legislature itself has considered the discretionary nature of the appeal board’s authority. Naturally, *738I would assume that the Legislature was aware when enacting 1985 PA 103, as well as when enacting the language at issue, what meaning this Court has attached to the word "discretion.” Cash, Michigan Gas Storage Co, supra. See also Spalding v Spalding, 355 Mich 382; 94 NW2d 810 (1959).
I agree with the majority that the discretionary nature of the appeal board’s authority over petitions for additional testimony practically limits the ability of any party to present new issues during an appeal. We should consider the exceedingly narrow scope of review of the denial of a petition for additional testimony when deciding whether parties can and therefore must present these issues before the appeal board.
In deciding whether the plaintiffs claim should be precluded by the doctrine of merger, we must also consider the present controversy in our Court of Appeals over the scope of review accorded the appeal board. Cf. Kingery v Ford Motor Co, 116 Mich App 606, 614; 323 NW2d 318 (1982) (review de novo does not permit the raising of a new issue which was not presented earlier), with Roberts v Marquette General Hosp, 127 Mich App 301, 304; 338 NW2d 393 (1983) (it is within the appeal board’s de novo review authority to consider issues not previously raised). Moreover, we must consider the powerful disincentive to delaying these claims presented in the one-year back rule of § 833, MCL 418.833(1); MSA 17.237(833)(1).15 We must consider the general but well-recognized thesis that work*739ers’ compensation proceedings are intended to be summary administrative proceedings rather than contentious litigation. Hebert, supra.
Finally, in deciding whether the doctrine of merger precludes plaintiff’s second petition, we must consider our own prior decisions in this area. In fact, the identical issue presented in this case was previously considered and resolved in White v Michigan Consolidated Gas Co, supra, (White II).
In White v Michigan Consolidated Gas Co, 342 Mich 160; 69 NW2d 160 (1955) (White I), a unanimous Court held that the plaintiff was entitled to a closed period of compensation from May 21, 1951, until November 7, 1952. The case was remanded for entry of an order consistent with the Supreme Court’s opinion. On June 9, 1955, three months after this Court’s decision, the same plaintiff filed a new petition alleging a change of condition dated November 7, 1952. As in the instant case, the date of the change of condition alleged by White coincided with the expiration of the closed period previously adjudicated. As in the instant case, the change of condition alleged actually preceded the date of the appellate commission’s initial decision.16
The appellate commission nonetheless ordered continuing compensation from the date of the change of condition. This Court affirmed in White II, explaining:
We deal in this case with an instance of temporary total disability. In such a situation, the device employed by the appeal board in ordering payment of compensation until further order of the board, we have many times approved. Hovey v General Construction Co, 233 Mich 531 [207 NW 852 *740(1926)]; Warner v Michigan Electric Railway Co, 248 Mich 60 [226 NW 887 (1929)]; Pretzer v State Psychopathic Hospital, 286 Mich 454 [282 NW 213 (1938)]; Lynch v Briggs Mfg Co, 329 Mich 168 [45 NW2d 20 (1950)].
Such an order does not finally determine rights to compensation. A petition to stop, to decrease or to increase compensation is always permissible in order to show circumstances concerning a claimant’s physical condition which have changed from the last date of hearing. Hood v Wyandotte Oil & Fat Co, supra; Catino v Morgan & Wright Co, 272 Mich 154 [261 NW 281 (1935)]; Goines v Kelsey Hayes Wheel Co, 294 Mich 156 [292 NW 686 (1940)]. Indeed, in view of plaintiffs age and the nature of the injury, it is to be hoped that time or further medical treatment will occasion still further consideration of this case.
We believe that what has been said serves to answer appellant’s contention that the previous order of this Court in White v Michigan Consolidated Gas Co, supra, was res judicata as to compensation claimed between the dates of November 7, 1952 (the previous referee’s hearing date) and June 4, 1954 (the previous appeal board order date). [White II, 352 Mich 210-211.]
Indistinguishable facts were also presented in Morgan v Freedman Artcraft, 401 Mich 54; 257 NW2d 85 (1977), in which a unanimous Court, following White II, held that res judicata did not preclude a subsequent petition.
The subsequent treatment of White II, casts some doubt upon other aspects of the opinion, although in my view its specific ruling on res judicata remains intact. See, e.g., Sanford v Ryerson & Haynes, Inc, 396 Mich 630, 637; 242 NW2d 393 (1976) (rejecting White IFs use of a "competent” evidence standard of review over administrative fact finding). Perhaps the most problematic treatment of White II was in Gose, where the majority explained:
*741"While the doctrine of res judicata does apply to workmen’s compensation cases (Willis v Michigan Standard Alloy Casting, 367 Mich 140 [116 NW2d 222 (1962)]), in Michigan it has been limited to issues that were actually litigated as a matter of fact. Hebert v Ford Motor Co, 285 Mich 607 [281 NW 374 (1938)]; White v Michigan Consolidated Gas Co, 352 Mich 201 [89 NW2d 439 (1958)].”
A close reading of both Hebert and White shows that neither opinion delineated a rule unique to workers’ compensation proceedings; they merely recited a narrow application of the rule, as opposed to a broad version, discussed infra. Moreover, in each case, res judicata was inapplicable: two separate injuries involving two separate transactions were at issue in Hebert, and in White a final determination on the merits had not been made in the first proceeding. [Gose, supra, p 159, n 1. Quoting with approval Stokes v Lakey Foundry Corp, 20 Mich App 217, 219; 173 NW2d 832 (1969).]
In fact, as can be seen in a close reading of White I and White II, there was a "final” decision, although the matter was remanded by this Court for entry of the order of the appellate commission. Thus, White II, actually involved a new petition, a collateral attack on the prior adjudication.
Furthermore, although the Gose majority adopted a broad rule of res judicata, the narrow rule set forth in White II was merely an alternative basis for its holding. Thus, in White II, it was further explained:
Obviously, in the period between the referee’s hearing and appeal board decision, the crucial facts pertaining to disability could change to the advantage of either party without any adjudication upon such change. This was recognized in the order of the appeal board, ending "until the further order of the workmen’s compensation department.” [Id., p 211.]
*742Indeed, in my view, it is this reasoning, and not a narrow rule of res judicata, which explains the White II holding, since the question of plaintiff’s continuing disability was actually litigated in the prior proceeding.
The reasoning of this Court in White II is fully consistent with the exception to the doctrine of merger set forth in 1 Restatement Judgments, 2d, § 26(d). Moreover, I believe that White II is indistinguishable from the instant case. Given the nature of this statutory scheme, it is simply unreasonable to suggest either that plaintiff could have or should have presented her petition on the basis of a change of condition to the appeal board in the first appeal under penalty of forfeiture. Indeed, as the majority has pointed out, there is little sense in burdening the appeal board at this late date with an avalanche of protective petitions. The irony of doing so in furtherance of a rule of judicial economy is inescapable.17
It is for these reasons, lying within general res judicata doctrine and sound public policy, that I concur in the holding of the majority. The decision of the Court of Appeals should be reversed and the award of the appeal board should be reinstated.
Cavanagh, J., concurred with Boyle, J._

 1 am inclined to believe that it is the doctrine of merger which is at issue, since the order of the bureau was in favor of the plaintiff on the issue of continuing disability. See 1 Restatement Judgments, 2d, § 18, p 151; cf. § 19, p 161.

 As a basis for his decision in Pike, supra, p 602, Justice Griffin has cited either a change in the law as a general exception to res judicata or the possibility that any collateral attack on the amount of benefits, as opposed to the entitlement to benefits, presents an exception to res judicata. Similarly, Justice Brickley has based his decision in Pike, supra, p 607, on the suggestion that there was an unspecified "changed circumstance” that in context must be the conclusion that the statute is unconstitutional. Despite these differences, it appears that all would agree that the broad rule of res judicata is applicable to these proceedings.

 MCL 418.851; MSA 17.237(851) provided:
The hearing referee assigned to any hearing in accordance with the provisions of section 847 shall make such inquiries and investigations as he shall deem necessary. The hearing shall be held at the locality where the injury occurred and the order of the hearing referee shall be filed with the bureau. Unless a claim for review is filed by a party within 15 days, the order shall stand as the order of the bureau.

 MCL 418.861; MSA 17.237(861) provided:
The court of appeals and the supreme court shall have power to review questions of law involved in any final order of the [appeal] board, if application is made by the aggrieved party within 30 days after such order by any method permissible under the rules of the courts of the laws of this state.

 In fact, it appears that the date alleged for the change of plaintiffs condition, and that ultimately found by the appeal board, was the date of the hearing referee’s initial decision, December 6, 1972.

 Askew v Ann Arbor Public Schools, unpublished opinion per curiam of the Court of Appeals, decided June 12, 1986 (Docket No. 82704).

 As explained in 1 Restatement Judgments, 2d, § 24, comment a, pp 196-197:
"Claim,” in the context of res judicata, has never been broader than the transaction to which it related. But in the days when civil procedure still bore the imprint of the forms of action and the division between law and equity, the courts were prone to associate claim with a single theory of recovery, so that, with respect to one transaction, a plaintiff might have as many claims as there were theories of the substantive law upon which he could seek relief against the defendant. Thus, defeated in an action based on one theory, the plaintiff might be able to maintain another action based on a different theory, even though both actions were grounded upon the defendant’s identical act or connected acts forming a single life-situation. . . .
The present trend is to see claim in factual terms and to make it coterminous with the transaction regardless of the number of substantive theories, or variant forms of relief flowing from those theories, that may be available to the plaintiff; regardless of the number of primary rights that may have been invaded; and regardless of the variations in the evidence needed to support the theories or rights. The transaction is the basis of the litigative unit or entity which may not be split.

 See n 7.

 It should be noted that not all claims under the Workers’ Disability Compensation Act are for wage-loss benefits. Medical and rehabilitation benefits, MCL 418.319; MSA 17.237(319), death benefits, MCL 418.321; MSA 17.237(321), and specific-loss benefits, MCL 418.361(2); MSA 17.237(361X2), are also provided for under the act.

 See, generally, comment, Disability under the Michigan worker’s compensation act, 62 U Det L R 433 (1985).

 This is not to say that, in effect, requiring the appeal board to grant a petition for additional testimony on the basis of an alleged change of physical condition is the more efficient procedural method of addressing these questions. See part hi.

 The Act requires an injured worker to establish four elements before an employer will be held liable for the worker’s injuries. First, there must be a personal injury. Second, the injury must arise out of and in the course of employment. Third, the employer must have notice of the injury. Last, the employee must make a formal claim for compensation within the statutory period. [Comment, n 10 supra, p 436. Citations deleted.]

 While a plurality of the Court in Pike and Riley has abandoned the rule of res judicata in workers’ compensation proceedings, the rule of collateral estoppel has not yet been abandoned. See, generally, 1 Restatement Judgments, 2d, § 27, p 250. Cf. Storey v Meijer, Inc, 431 Mich 368; 429 NW2d 169 (1988) (doctrine of collateral estoppel does not preclude relitigation of factual issues in circuit court when previously litigated in mesc hearings).

 See n 9.

 Section 833(1) provides:
If payment of compensation is made, other than medical expenses, and an application for further compensation is later filed with the bureau, no compensation shall be ordered for any period which is more than 1 year prior to the date of filing of such application.

 The appellate commission was the statutory predecessor of the current Workers’ Compensation Appeal Board.

 As explained by one commentator, the finality of res judicata is intended to promote judicial economy:
A good place to start critical analysis of the whole matter is with the question: why should not a party be compelled to join all the claims which it may join? Surely something is to be gained from wiping a slate clean, and it has been urged that the law should require this result when parties invoke its processes to settle some of their disputes. Wherever there will be a large overlap of issues or evidence if two trials are held, it is wasteful to society and harassing to the adversary to have more than one, and there should be no more than one unless there is some very good reason. [James & Hazard, Civil Procedure (3d ed), § 11.8, pp 599-600. Emphasis in the original.]