COURT OF APPEAL FOR ONTARIO

CITATION: Canada Post Corporation v. Canadian Union of Postal
    Workers, 2019 ONCA 476

DATE: 20190611

DOCKET: C65334

Feldman, van Rensburg and Nordheimer JJ.A.

BETWEEN

Canada Post Corporation

Appellant

and

Canadian Union of Postal Workers

Respondent

Richard J. Charney and Kaley Dodds, for the appellant

Paul J.J. Cavalluzzo and Adrienne Telford, for the
    respondent

Heard: November 26, 2018

On appeal from the order of the Divisional Court (Regional
    Senior Justice Robbie D. Gordon and Justice Frances P. Kiteley, Justice Herman
    J. Wilton-Siegel dissenting), dated November 2, 2017, with reasons reported at
    2017 ONSC 6400, affirming the award of Arbitrator Owen B. Shime, dated
    September 21, 2016, with reasons reported at [2016] C.L.A.D. No. 264, 2016
    CarswellNat 5923.

van
    Rensburg J.A.:

OVERVIEW

[1]

This appeal began with the arbitration of a
    grievance concerning the dismissal of Christopher Seivright, a temporary postal
    worker and member of the Canadian Union of Postal Workers (the respondent or
    the Union"). The arbitrator allowed the grievance and ordered Mr.
    Seivrights reinstatement. Canada Post Corporation (the appellant or the
    Corporation) filed an application for judicial review of the arbitrators award,
    that was dismissed by the Divisional Court. The Corporation now appeals to this
    court with leave.

[2]

At the heart of the case is the interpretation
    of Article 44.11(b) of the parties collective agreement authorizing the
    termination of employment of a temporary worker who fails to demonstrate
    reasonable availability in the acceptance of work assignments in any six
    consecutive month period.

[3]

The employment of Mr. Seivright, a temporary
    employee at the York Distribution Centre (the YDC) was terminated when, between
    February 26 and August 29, 2015, he accepted 57 of 151 work assignments that
    were offered to him. The Corporation terminated his employment because his
    acceptance rate (37.8%) was below the average of 49.9% for his peer group,
    consisting of all the temporary employees in the YDC, during the same six-month
    period. The Union grieved the termination.

[4]

The arbitrator considered the grievance and concluded
    that both the use of an acceptance rate benchmark and its application to the
    grievor were unreasonable. He held that the Corporations use of a bare
    arithmetical formula of comparing the employees acceptance rate with the peer
    average was arbitrary and failed to consider factors such as the 24/7 operation
    of the YDC, the high volume of parcels passing through the facility, the
    resulting use of temporary workers, and the grievors seniority  all of which increased
    how often the grievor was called for work. Instead, the arbitrator found that
    the Corporation ought to have considered the actual number of shifts worked by
    the grievor, and the fact that the Corporation suffered no prejudice in the
    form of delayed mail delivery as a result of the grievors non-acceptance of
    work. The arbitrator observed that, when the relevant factors were considered,
    the grievor had been reasonably available to accept work assignments. He set
    aside the dismissal and ordered the grievors reinstatement.

[5]

On judicial review, the Divisional Court
    concluded that the arbitrator departed from binding arbitral jurisprudence in two
    respects  in rejecting an acceptance rate approach to assess reasonable
    availability, and in requiring prejudice to the Corporation as a pre-condition
    for termination. Gordon R.S.J., for the majority, nevertheless upheld the arbitrators
    decision to reinstate Mr. Seivright on the basis that his decision, although
    flawed in certain respects, was reasonable. Wilton-Siegel J., in dissent, would
    have set aside the arbitrators decision and remitted the grievance to a new
    arbitrator for determination.

[6]

For the reasons that follow, I would dismiss the
    Corporations appeal from the Divisional Courts decision. Briefly, I reject
    the appellants argument that the result in this case departed from binding
    arbitral jurisprudence interpreting Article 44.11(b) of the collective
    agreement, and was therefore unreasonable. The arbitrator was entitled to go
    beyond the grievors acceptance rate and to consider other relevant
    circumstances in assessing the reasonableness of his availability. In this
    case, the relevant circumstances included the number of shifts offered to the
    grievor, the manner in which those offers were made, the total number of shifts
    and hours he actually worked, and the nature of the YDCs operations. And,
    although the arbitrator erred in requiring prejudice to the Corporation as a
    pre-condition for termination, this error did not affect the reasonableness of his
    decision.

[7]

The arbitrators award, allowing the grievance
    and reinstating the grievor after due consideration of the relevant
    circumstances, was reasonable. The Corporation failed to take into
    consideration the relevant factors, with the result that the termination of the
    grievors employment was unjustified.

FACTS

[8]

Christopher Seivright was employed as a
    temporary postal worker at the YDC from November 2, 2011 until his employment
    was terminated on September 17, 2015. He was on a list of temporary or casual
    employees called, in order of seniority, to fill in for absent full or
    part-time employees, or otherwise as required by the workload at the YDC.
    Temporary workers are offered shifts on an as-needed basis, without guaranteed
    minimum hours of work per week. At the time of Mr. Seivrights termination, there
    were approximately 70 temporary employees on the YDC call list.

[9]

Until October 28, 2014, when Canada Post
    implemented the Eclipse Automated Calling System nationally,
[1]
shifts were offered by
    management personnel to temporary employees at the YDC in order of seniority,
    and no such employee was disciplined for not accepting a shift. Under the
    Eclipse system, computerized calls are made at various times of the day (but
    typically not before 7:00 a.m.), seven days a week, without regard to whether
    an employee has just completed a shift. When an employee answers the call,
    there is an automated message with the assignment details and the employee can either
    accept or reject the offer of a shift using the telephone keypad. An assignment
    is considered not accepted when it is explicitly rejected, or when the
    employee cannot be reached and does not return the call within ten minutes. If
    more than one work assignment is offered for one day and some or all are
    rejected by the employee, the rejections count as a single refusal. Temporary
    employees are not called when they are on a sanctioned leave, including the two-week
    vacation to which they are entitled.

[10]

Temporary employees are required to demonstrate
    reasonable availability in the acceptance of work assignments. Article
    44.11(b) of the collective agreement provides that the employment of a
    temporary employee shall be terminated when the employee has not demonstrated
    such reasonable availability in any six-month period.

[11]

From June 2014, parcel distribution at the YDC
    increased significantly, which led to five new full-time workers being hired,
    and the increased use of temporary workers. Beginning in August 2015, the YDC
    operated 24 hours a day for seven days a week, but had begun testing a seven
    day work week in June 2015, by introducing a Sunday afternoon shift.

[12]

The number of shifts offered increases with
    seniority. During the relevant six-month period Mr. Seivright, who was the
    seventh most senior temporary employee, worked 57 shifts, which was within the
    top 25 to 30% of all temporary employees in the YDC. He received 230 calls (of
    which 151 were counted), and was offered more assignments in total than it was
    possible to work.

[13]

Mr. Seivright received two warning letters
    before his termination. On May 25, 2015, he was informed that, between November
    5, 2014 and April 25, 2015, he had accepted 39 of 131 offers made, and that
    this was unacceptable. The letter did not inform Mr. Seivright of his
    acceptance rate (29.8%) or that this was being compared to the peer average (39.1%)
    for that period. The letter stated that Mr. Seivrights level of availability [had]
    not been sufficient to meet [the Corporations] business needs and customer
    service standards.

[14]

A July 10, 2015 letter advised that, between
    April 26 and June 27, 2015, Mr. Seivright had accepted 19 of 52 offers of work
    assignments, which was unacceptable. Again, the letter did not inform Mr.
    Seivright of his acceptance rate (36.5%), and while it told him for the first
    time that he was being compared to his peers, it did not refer to the peer
    average of 49.7%. Mr. Seivright was warned in the letter that if he continued
    to demonstrate unreasonable availability in the next two months, his employment
    could be discontinued.

[15]

On September 17, 2015, Mr. Seivrights
    employment was terminated. The stated reason for the termination was that he
    had not demonstrated reasonable availability in the acceptance of work
    assignments during the six-month period from February 26, 2015 to August 29,
    2015.

[16]

During the relevant six-month period, Mr.
    Seivright accepted 57 of the 151 work assignments offered. This was the 17th
    highest number of shifts worked, in the top 25 to 30% of all temporary
    employees at the YDC, and an average of 13.5 hours per week. Mr. Seivrights
    acceptance rate was 37.8%, while the average acceptance rate of all temporary
    employees at the YDC during the same period was 49.9%. To meet the peer
    average, Mr. Seivright would have had to have worked 3.5 shifts per week,
    roughly equivalent to part-time hours.

[17]

The Union grieved the termination, alleging that
    the grievor had been reasonably available to work, such that his dismissal was
    unjust and unreasonable.

RELEVANT PROVISIONS
    OF THE COLLECTIVE AGREEMENT

[18]

Article 44.11(b) was first introduced in the
    collective agreement signed September 30, 2003. The relevant provisions of the
    collective agreement in force at the time of Mr. Seivrights dismissal,
    including Article 44.11, are as follows.

9.100.
Restriction of Power

The arbitrator shall not modify the provisions
    of this collective agreement.

9.103.
Future Cases

The final decision rendered by an arbitrator
    binds the Corporation, the Union and the employees in all cases involving
    identical and/or substantially identical circumstances.

10.01.
Just Cause and Burden of Proof

(a) No disciplinary measure in the form of a
    notice of discipline, suspension or discharge or in any other form shall be
    imposed on any employee without just, reasonable and sufficient cause and
    without his or her receiving beforehand or at the same time a written notice
    showing the grounds on which a disciplinary measure is imposed.

10.08.
Termination of Employment

Article 9 and clause 10.01 shall apply mutatis
    mutandis to any form of termination of employment decided by the Corporation.

44.11.
Availability and Termination of
    Employment

(a) The employment of a temporary employee may
    be terminated by the Corporation when the employee has not worked for any
    reason during a period of twelve (12) continuous months excluding the period
    from December 1 to December 24 inclusive.

Following a review of its operational
    requirements, should the Corporation decide to partially exercise its right in
    this regard, the identification of the employees who will be terminated will be
    by reverse order of seniority.

(b) The employment of a temporary employee
    shall be terminated when the employee has not demonstrated reasonable
    availability in the acceptance of work assignments during any six (6)
    consecutive months following the signing of the collective agreement.

Paragraphs 44.11
    (a) and (b) do not apply with respect to any period during which an employee is
    disabled, on maternity, parental, adoption or union leave without pay, provided
    however that prior written notice has been given to the Corporation.

THE ARBITRATION DECISION

[19]

The arbitrator began his reasons by summarizing
    some of the evidence at the arbitration. Of note was the evidence of Mark
    Alexander, Manager of Production Control and Reporting, who testified about the
    Corporations approach to termination in this case. Mr. Alexander was
    responsible for staffing levels for temporary employees and for the Eclipse system
    and its implementation. In consultation with the Corporations National Labour
    Relations Division and the National Production Control and Reporting Division,
    he conceived of the practice of utilizing a peer acceptance rate for
    determining reasonable availability.

[20]

Mr. Alexander confirmed that he had discharged
    Mr. Seivright because he continually had fallen below the peer average at YDC
    and because he had been notified twice about his availability and had not
    improved. Mr. Alexander did not consider the high number of calls the grievor
    received because of his level of seniority, or that the YDC was a 24/7
    operation. Mr. Alexander was not aware of whether customer service was affected
    by Mr. Seivrights unavailability and this was not a factor he considered. Mr.
    Alexander acknowledged that the peer average was a moving target that varied
    from time to time.

[21]

The resources planning officer at the YDC, the
    grievance officer for Mr. Seivrights Union local and Mr. Seivright also
    testified at the arbitration hearing. In evidence were various documents,
    including the grievors letter of hire, the warning letters, the letter of termination,
    records of work assignment offers made to Mr. Seivright, and various corporate policies
    and guidelines.

[22]

Mr. Seivrights letter of hire dated November 1,
    2011 said in relation to Article 44.11 of the collective agreement:

Canada Post counts on your availability as a
    temporary employee. Pursuant to clause 44.11 of your collective agreement, you
    have the obligation to demonstrate reasonable availability in the acceptance of
    work assignments.

Canada Post
    expects you to be available for work. Consequently, depending upon the
    circumstances of each case, unsuccessful attempted calls or repetitive refusal
    of work assignment offers will be documented [in] accordance with clause
    44.11(b) of the collective agreement.

[23]

Mr. Seivright also signed a Directive Regarding
    the Obligation of Availability for Temporary Employees in the CUPW Bargaining
    Unit that set out Article 44.11 and stated:

Canada Post
    expects you to be available for work. Consequently, depending on the
    circumstances of each case, unsuccessful attempted calls or repetitive refusals
    of work assignment offers will be documented and may lead to your termination
    of employment from Canada Post in accordance with clause 44.11(b) of the
    collective agreement.

[24]

The arbitrator set out in detail the arguments
    of the parties. In brief, the Union argued that the peer acceptance rate
    approach to determining whether the grievor was reasonably available was unreasonable
    in the context of the high parcel volume at YDC, the shortage of permanent
    staff and the inordinate number of calls to the grievor during the six-month
    period. It led to absurd results when applied to employees with greater seniority:
    in the six-month period, the grievor worked 57 shifts and had an acceptance
    rate of 37.8%, while a less senior employee who worked only two shifts had a
    100% acceptance rate. The Union argued that the Corporation failed to consider
    a number of relevant factors, including: the casual nature of the temporary
    employment and the fact that temporary employees might have outside employment,
    that the YDC operated 24 hours a day, seven days a week, so that work offers
    could be made daily and would increase with an employees seniority, and the
    fact that at the time there were approximately 70 employees on the temporary
    employee list, sufficient such that there was no prejudice to the Corporation.
    The Union also asserted that certain work offers should not have been counted
    against the grievor, such as early morning calls after Mr. Seivright had worked
    a night shift or calls on Sundays when he was observing the Sabbath, and that
    the grievors personal circumstances, including the need for accommodation due to
    family obligations and religious observance, ought to have been considered.
    Finally, the Union submitted that the grievor did not have proper notice of the
    standard that the Corporation applied to him.

[25]

The Corporation argued that the grievors dismissal,
    based on a comparison of his rate of acceptance to the peer average, was
    warranted. It asserted that prior arbitral jurisprudence was binding under
    Article 9.103 of the collective agreement, and supported the proposition that
    an acceptance rate of less than 50% did not constitute reasonable availability.
    The Corporation rejected the assertion that only certain calls, or that any of
    Mr. Seivrights personal circumstances, should be considered. Instead, all
    calls should be counted, including those made to Mr. Seivright in the early
    morning hours after he had just completed a night shift, and those requiring
    him to work on Sundays. According to the Corporation, it was a term of the
    grievors employment that he be available at any time, and his failure to meet
    the peer average constituted unreasonable availability.

[26]

Arbitrator Shime allowed the grievance and ordered
    Mr. Seivrights reinstatement. He accepted that Articles 10 and 44 of the
    collective agreement must be read together, such that where a temporary
    employee does not demonstrate reasonable availability in the acceptance of work
    assignments during any six-month period, such conduct constitutes just cause
    for the termination of employment, and the arbitrator must uphold the termination.
    He went on to state, at para. 57:

However, that
    does not end the matter, because such a determination, as the cases reveal,
    requires a factual assessment in each case as to what constitutes reasonable
    availability. Because the end product of such a determination or assessment may
    lead to termination or discharge for just cause, the underlying facts must bear
    the same scrutiny as any other factual basis relied upon by the Corporation to
    terminate or discharge an employee for just cause.

[27]

The arbitrator noted that Article 44.11(b) does
    not mandate consideration of a
rate
of acceptance based on total
    assignments offered, for the purpose of determining reasonable availability in
    the acceptance of work assignments. In fact,  the effect of measuring acceptance
    as a percentage of the assignments offered is to automatically dilute the
    actual acceptances of work assignments to the detriment of the temp: at para.
    60. Nor is there a mandate in the collective agreement to measure a temporary
    employees acceptance against the peer average to determine reasonable
    availability.

[28]

The arbitrator noted that the grievors
    automatic termination was contrary to the Corporations guidelines, which
    provide that the Corporation or managers do not action every refusal or
    attempted call, [and are] to evaluate each case individually based on its
    merits. He referred to the directive that lists may cover a 24/7 period; the
    expectation for availability may be lower when he concluded that the
    Corporation ought to have considered the context of the YDCs 24/7 operation
    and the increased high volume of parcels as well as the grievors increasing
    seniority in order to determine reasonable availability. Rather than applying
    the rate of acceptance formula to the seniority list, the Corporation ought to
    have counted the number of shifts accepted. The arbitrator noted that the
    automatic application of the acceptance rate formula did not consider Mr.
    Seivrights actual acceptances, which compared favourably to the hours worked
    by permanent part-time employees.

[29]

In the arbitrators view, the Corporations use
    and application of the 50% acceptance rate was arbitrary and unreasonable. Article
    44.11(b) did not include either a numerical threshold below which availability
    would be deemed unreasonable, or a requirement that temporary employees
    acceptance rates be compared to the peer average. The temporary employees had
    not been notified of any such standard, and in any event the average acceptance
    rate of temporary workers at the YDC was in constant flux and unknowable in
    advance.

[30]

In the course of his reasons, the arbitrator
    observed that, when considering reasonable availability, the interests of the
    employer in maintaining the proper standards for the delivery of mail must be
    weighed along with the interests of the temporary employee in maintaining an
    element of job security and financial support. He went on to conclude that a
    mechanical application of the formula was unfair and arbitrary as it bore no
    relation to a level of availability that was required to satisfy business needs
    and customer service standards.  He went so far as to state that a temporary
    employee should not be terminated unless his or her unavailability impaired the
    standards of delivery.

[31]

Finally, the arbitrator concluded that, on the
    facts of this case, the Corporation did not have just, reasonable and
    sufficient cause to terminate Mr. Seivrights employment, as in all the
    circumstances he had demonstrated reasonable availability in the acceptance of
    work assignments.

THE DIVISIONAL COURT DECISION

[32]

A majority of the Divisional Court (Gordon
    R.S.J. and Kiteley J.) upheld the arbitrators decision as reasonable.
    Wilton-Siegel J. dissented.

[33]

The majority held that the arbitrator departed
    from binding arbitral jurisprudence both in failing to use an acceptance rate
    analysis and in requiring prejudice to the employer as a pre-condition to
    termination.

[34]

In the majoritys view, the arbitrators
    decision was nevertheless reasonable. It was reasonable for the arbitrator to
    conclude that both the acceptance rate standard of 50% and its application to
    Mr. Seivright were unreasonable. Gordon R.S.J. stated, at paras. 27-28 and 37-38:

The Arbitrator in the case before us
    determined that the rate used was unilateral and arbitrary because, inter alia,
    it failed to take into consideration: (a) the 24/7 period of operation at the
    facility in question; (b) the high increase in the volume of parcels at the
    facility; and (c) what impact a 50% acceptance rate would have on the
    Corporations ability to meet its mandate.

In my view, the Arbitrator did not disregard
    arbitral jurisprudence in this respect. His determination that the acceptance
    rate used by the Corporation was both unilateral and arbitrary was reasonable.

It is clear from the decision of the
    Arbitrator that neither of these requirements [for the standard itself and the
    application of the standard to be reasonable] were met. As indicated above, the
    Arbitrator was justified in finding that the standard used by the Corporation
    was arbitrary. Furthermore, he determined that the application of the standard
    to the Grievor was not reasonable because: (1) It failed to consider the number
    of work assignments accepted by the Grievor and how this compared to other
    part-time employees; (2) It failed to consider his seniority and the consequent
    increase in offers made to him; and (3) It failed to consider that the very
    nature of certain offered work assignments rendered them incapable of
    acceptance.

Based on these
    factors it was reasonable for the Arbitrator to have found that the Corporation
    did not meet its onus of establishing that the Grievors rate of acceptance was
    unreasonable.

[35]

Wilton-Siegel J. concluded that the arbitrators
    reasoning was fundamentally flawed because he failed to follow arbitral
    jurisprudence which established that a dismissal may be made on the basis of an
    acceptance rate, and to the extent the arbitrator held that proof of harm to
    the Corporation was required for a dismissal.

[36]

Wilton-Siegel J. accepted that the arbitral
    jurisprudence establishes that an acceptance rate materially below 50% is
    sufficient for termination, and that therefore the Corporations use of such a
    standard in this case was reasonable. Even if the factors identified by the
    arbitrator (24/7 operation of the YDC and the increase in the volume of
    parcels) ought to be taken into consideration, these factors were accounted for
    in the peer average because such circumstances would apply equally to all YDC
    employees.

[37]

Wilton-Siegel J. also concluded that the
    Corporation applied the acceptance rate standard to the grievor in a reasonable
    manner, when his acceptance of work assignments was compared to that of other temporary
    employees by incorporating the peer average. There was no basis for comparing the
    grievors hours to those of a part-time employee. Finally, Wilton-Siegel J. rejected
    as a relevant factor the impact of the grievors seniority on the number of
    offers made, saying that considering this factor would amount to rewriting the
    collective agreement.

[38]

Wilton-Siegel J. held that the Corporations use
    and application of the acceptance rate formula in this case was reasonable and
    supported by arbitral jurisprudence, and that, in failing to follow the
    jurisprudence, which was binding by virtue of Article 9.103 of the collective
    agreement, the arbitrators decision was unreasonable.

STANDARD OF REVIEW

[39]

The parties agree that the standard of review of
    the arbitrators award is reasonableness. The Supreme Court of Canada defined
    the reasonableness standard in
Dunsmuir v. New Brunswick
, 2008 SCC 9, [2008] 1 S.C.R. 190, at para. 47:

A court
    conducting a review for reasonableness inquires into the qualities that make a
    decision reasonable, referring both to the process of articulating the reasons
    and to outcomes. In judicial review, reasonableness is concerned mostly with
    the existence of justification, transparency and intelligibility within the
    decision-making process. But it is also concerned with whether the decision
    falls within a range of possible, acceptable outcomes which are defensible in
    respect of the facts and law.

[40]

On appeal to this court, we must determine
    whether the reviewing court correctly identified and properly applied the
    appropriate standard of review. In other words, this court on appeal
    effectively steps into the shoes of the Divisional Court, focusing on the reasonableness
    of the arbitral decision itself:
Agraira v. Canada (Public Safety and
    Emergency Preparedness)
, 2013 SCC 36, [2013] 2 S.C.R. 559, at paras.
    45-47.

ISSUES

[41]

The appellants central argument in this appeal
    is that the arbitrator failed to follow prior arbitral jurisprudence when he
    rejected the Corporations termination of the grievors employment that was
    based solely on his failure to meet the peer average acceptance rate.

[42]

The appellant says that the arbitrators
    decision, which rejected this approach and imported other considerations into
    determining whether reasonable availability was demonstrated, contravened
    Article 9.103 of the collective agreement and was unreasonable. Alternatively,
    the arbitrators failure to explain why he departed from the prior arbitral
    cases in itself rendered the decision unreasonable, as it lacks the necessary
    justification, transparency and intelligibility that are required for appellate
    review.

[43]

The determination of the appeal engages a number
    of issues, which will be canvassed in my analysis.

[44]

First, I will consider what was, and was not,
    determined in the prior arbitration cases considering Article 44.11(b), which,
    under Article 9.103 of the collective agreement, are binding on the parties to
    the extent that they involved identical or substantially identical
    circumstances. I will examine the appellants argument that these earlier cases
    consistently endorse the Corporations use of an acceptance rate test in determining
    whether a temporary employee has demonstrated reasonable availability in the
    acceptance of work assignments.

[45]

As I will explain, the prior arbitral
    jurisprudence does not support the appellants position. While a number of
    cases used a 50% acceptance rate as an administrative screening device, there is
    simply no arbitral precedent for an automatic or mechanical termination based
    on a peer average, or even a rate of 50%. Rather, the cases, consistent with
    the Corporations own policies, require a review of the particular
    circumstances of the workplace, which in this case, unlike any of the prior
    arbitral cases, involved temporary employees on a single list who could be offered
    work 24 hours a day, seven days a week.

[46]

In view of this conclusion, it is unnecessary to
    consider the appellants arguments that the arbitrators failure to follow
    binding arbitral jurisprudence in itself, or his failure to explain why he
    departed from such jurisprudence, rendered his decision unreasonable.

[47]

The next issue is whether there was any error in
    the arbitrators analysis that made his decision unreasonable. I accept the
    appellants argument (also accepted in the Divisional Court) that the
    arbitrators insistence on prejudice to the Corporation as a pre-condition to
    termination, was inconsistent with the prior arbitral jurisprudence, and
    therefore an error. However, I agree with the majority of the Divisional Court
    that this error was not essential to the arbitrators decision allowing the
    grievance, which was otherwise reasonable.

[48]

Another issue raised by the appellant is whether
    it was denied procedural fairness when the arbitrator relied on the corporate
    prejudice factor, when it was not argued on the arbitration. In view of my
    conclusions on the corporate prejudice issue, it is unnecessary to determine
    this issue.

ANALYSIS

1.

What Did the Prior Arbitration Decisions Determine?

[49]

Pursuant to Article 9.103 of the collective
    agreement, prior arbitral awards involving identical and/or substantially
    identical circumstances are binding on the parties. This article is meant to
    prevent re-litigation, delay, costs and the risk of inconsistent results:
Canada
    Post Corp. v. Canadian Union of Postal Workers
(2001), 56
    O.R. (3d) 457 (C.A.), at para. 29. At the time of the arbitration, there were six
    arbitral decisions that considered Article 44.11(b). Two of these decisions
    were appealed first to the Superior Court of Quebec and then in 2008, to the
    Court of Appeal of Quebec.
[2]

[50]

A foundation of the appellants argument is that
    the prior arbitral awards endorse the mechanical use of an acceptance rate in
    determining reasonable availability, and that in fact a minimum 50% acceptance
    rate has been accepted consistently in the cases. The appellant argues that the
    arbitrator unlawfully amended the collective agreement by departing from prior
    arbitral awards involving similar circumstances, contrary to Article 9.103 of
    the collective agreement, and that therefore he exceeded his jurisdiction. The
    Corporation asserts that considerations other than the peer acceptance rate are
    personal circumstances or subjective considerations, which, according to the
    cases, are irrelevant.

[51]

The respondent disagrees with the Divisional
    Courts conclusion that the arbitrator departed from arbitral case law by failing
    to use the acceptance rate analysis. The Union argues that the binding
    arbitral jurisprudence does not dictate a formal acceptance rate test, but
    consistently calls for an analysis of the circumstances of each case. The Union
    also argues that, while the cases do not require corporate prejudice as a pre-condition
    to termination, they do not preclude its consideration as a factor in assessing
    reasonable availability.

[52]

I begin with what is not in dispute. The prior
    jurisprudence establishes that the termination of a temporary employee is justified
    once the Corporation establishes that the employee has not demonstrated
    reasonable availability, unless the termination was abusive, discriminatory, or
    due to an unreasonable personal motive against the grievor. The arbitrators
    jurisdiction is limited accordingly. Since the termination is not
    disciplinary, an arbitrator has no ability to impose a lesser sanction for
    the employees failure to demonstrate reasonable availability.  See, for
    example, the appellate review of the Sabourin and Rousseau Arbitrations, at
2008 QCCA 1232
, at para.
    13.

[53]

The cases observe that the collective agreement
    does not define reasonable availability, and that it is therefore necessary,
    and consistent with the Corporations own policies, to consider the individual
    circumstances of each case, in other words to conduct a case-by-case analysis:
    Thistle Arbitration, at p. 13;
Sabourin
    Arbitration,
at para. 7. At para. 9 of its decision,
    the Court of Appeal of Quebec stated:

[Translation]

[T]he arbitrators
    bore the responsibility of assessing, case by case, whether the temporary
    employee in question had demonstrated reasonable availability, although the
    collective agreement was silent on the definition of this concept.

[54]

I turn now to what the prior arbitral
    jurisprudence says about how reasonable availability is to be determined, and
    whether, as the appellant argues, the cases both endorse the use of an employees
    acceptance rate  the number of work offers accepted divided by the offers
    made  and establish that 50% is an appropriate cut-off rate for determining
    reasonable availability.

[55]

As the point of departure, I note that there is
    nothing in the prior arbitral jurisprudence that endorses or even refers to
    what occurred here  the use of a peer or average acceptance rate for
    temporary employees below which availability is mechanically determined to be
    unreasonable.

[56]

Nor is there anything in the prior arbitral
    jurisprudence that requires the use of a rate of acceptance when determining
    whether a particular temporary employee has demonstrated reasonable
    availability, or that would preclude the approach taken by the arbitrator in
    this case  which considered the actual number of shifts that were offered to
    the grievor and then worked by him, in the context of the 24/7 operations of
    the YDC.

[57]

The Corporations argument confuses the use of a
    50% benchmark as a screening device with a 50% acceptance rate standard for
    termination. In the earlier cases, the Corporation had identified the temporary
    employees whose acceptance rates fell below 50% and advised them to either
    increase their availability or face the risk of termination. However, with one
    exception, the Corporation had not adopted (and, in fact, expressly maintained
    that it was not making use of) such a standard as proof in itself that a
    particular employee was not reasonably available.

[58]

In the Blouin Arbitration, for example, the
    Corporation used a 50% benchmark to check, control, and, if necessary, purge its
    call-back lists of temporary employees, in anticipation of moving to use only
    temporary employees for weekend shifts: at paras. 19-20. Arbitrator
Blouin
described the 50%
    benchmark as the first step in the process and a simple work instrument to
    support an operational activity [the purging of the lists]: at para. 67. In
    the
Sabourin

Arbitration, the Corporation used a 50% standard as a starting point
    for reviewing the files of temporary employees. It was described as an administrative
    standard that was adopted to draw the line: at para. 23. In the Thistle Arbitration,
    the Corporation conducted a major review of availability records, which had focused
    on those employees who had not provided 50% availability: at p. 13. In the
Rousseau Arbitration, the Corporation
used the 50% standard as a first step after it decided to clean
    house because temporary employees were no longer reporting for work: at para.
    42.

[59]

In each of these cases, it was the Corporations
    position that it had
not
adopted a 50% benchmark, or any benchmark at
    all, for determining the reasonable availability of temporary employees: Blouin
    Arbitration, at para. 37; Sabourin Arbitration, at para. 23; Rousseau Arbitration,
    at para. 47. Arbitrator Thistle explained that no such standard was used
    because the employer did not want to low ball its expectation for
    availability: at p. 7.

[60]

While these cases do not compare the employees work
    acceptance rate to any particular standard, they do speak of the employees
    work acceptance both in the number of shifts offered and worked, and as a
    percentage of shifts offered. As the Union points out, in none of the cases was
    the standard applied by the Corporation to determine reasonable availability challenged,
    and in any event, the cases do not unanimously uphold the terminations of all
    temporary employees accepting less than 50% of work offers. Rather, the
    discharge of temporary employees with acceptance rates of anywhere from 3.3%
    to 45% were upheld, while the discharge of others with rates of 14% to 46% were
    not upheld.

[61]

It is important to note that there is no
    evidence that any of these cases involved a workplace with 24/7 operations and
    a call-in list for temporary employees, where an employee could be called upon
    to work any shift at any time.
[3]
In each of the Blouin, Sabourin and Rousseau Arbitrations, the grievors were on
    specific lists tied to a particular shift, and calls were made by an automated
    call generator to fill that shift. In the Rousseau Arbitration, temporary
    employees were placed on one of ten lists based on availability and could
    request transfer to another list. This was also the case in the Blouin Arbitration,
    where the grievors were all temporary employees on a weekend call-in list and
    could choose the hours during which they would be available. And, in the
    Sabourin Arbitration, the list on which each temporary employee was included
    also indicated the hours the employees could be contacted by the call generator
    (in some cases providing for a four hour call window, in others for a 5.5 hour
    call window, and in others for a window of various hours).

[62]

It is reasonable to assume that an employee who
    is on a list to be called up for particular shifts only, and who can change
    lists depending on his or her availability, holds him or herself out as
    available for work during that time period. Indeed, in upholding the
    terminations that were reversed in the Rousseau Arbitration (involving numerous
    employees on various shift-specific call-in lists), the Court of Appeal of Quebec
    observed at para. 18 that [s]omeone who is unavailable
most of the time he
    is supposed to be available
lacks reasonable availability (emphasis added).

[63]

The only case where the Corporation purported to
    define reasonable availability strictly through an acceptance rate benchmark
    was in the Second Lanyon Arbitration. In that case, the employer had set an
    acceptance rate of 70% which it had communicated to its temporary employees,
    including the grievor. Arbitrator Lanyon nevertheless concluded that the
    grievors injuries and exceptional daycare difficulties cas[t] substantial
    doubt on the Employers calculation of reasonable availability, and ordered
    the reinstatement of the employee: at para. 100.

2.

Did the Arbitrator Depart from Prior Arbitral Decisions?

[64]

It is impossible to extrapolate from the prior
    arbitral jurisprudence any general principle respecting the use of acceptance
    rates in the determination of whether a temporary employee has demonstrated
    reasonable availability in the acceptance of work assignments. The prior
    arbitral awards do not support what is argued by the appellant here  the
    requirement of an employee to meet the peer average or even a 50% availability
    rate as a proxy for reasonable availability. And, in any event, none of these
    cases involved circumstances comparable to the present case, where the grievor
    could be called in to work at any time 24 hours a day and seven days a week.

[65]

As such, there is no support in the arbitral
    jurisprudence for what would amount to an across-the-board reasonable
    acceptance rate or a mechanical application of such a rate. The arbitral
    jurisprudence points away from such an approach, by underlining the need for a
    case-by-case review of a grievors availability. I therefore disagree with
    the Divisional Courts conclusion at para. 24 that [i]n all of the arbitral
    jurisprudence the framework for analysis of reasonable availability has been
    the rate of acceptance of the employee. Rather, at its highest, the prior arbitral
    jurisprudence refers to both the employees actual work acceptances and their
    acceptance rates, while assessing reasonable availability on a case-by-case
    basis. But a mechanically applied acceptance rate has never been held to be either
    mandatory or determinative.

[66]

The arbitrator in this case therefore did not
    depart from the arbitral jurisprudence by considering factors other than Mr.
    Seivrights acceptance rate when assessing the reasonableness of his
    availability.

[67]

There are two additional questions to be
    considered in respect of the prior arbitral jurisprudence; however, it is
    unnecessary to express any definitive conclusion with respect to these issues.

[68]

First, I agree with the Corporations
    submission, also accepted by the Divisional Court, that there are no prior
    arbitral cases where it was required, as a pre-condition for termination, that
    the failure of the grievor to respond to offers of work must result in harm to the
    Corporations economic interests or impede mail delivery.

[69]

The cases accept that the reasonable
    availability requirement is intended to allow the Corporation to replace
    regular employees when they are absent and meet its service requirements
    without interruption. This is beyond dispute. Indeed, in this case, the
    grievors first warning letter specifically told him that his level of availability
    had not been sufficient to meet the Corporations business needs and customer
    service standards. In some cases, the Corporations specific needs during a
    busy period may well be relevant to the determination of reasonable
    availability. In the First Lanyon Arbitration, for example, the Corporations
    decision to review the availability of its five temporary employees occurred
    after a very busy Christmas season when it had relied on inside workers and
    supervisors to deliver the mail.

[70]

The Divisional Court accepted that the employers
    economic interests could be considered as a relevant factor. While I agree that
    there is nothing in the prior arbitral jurisprudence that would prevent the
    consideration of the Corporations economic interests, it is unnecessary to
    comment here on the extent to which, in a particular case, this factor could be
    taken into consideration in determining whether the temporary employee has
    demonstrated reasonable availability in the acceptance of work.

[71]

In my view, the Corporations failure to prove
    that Mr. Seivrights unavailability impeded mail delivery was not determinative
    of the arbitration. Lack of corporate prejudice was not, as the appellant
    argues, the lynchpin of the arbitrators award. Rather, as I explain in the
    next section, the arbitrators decision was based on his rejection of the
    Corporations arbitrary application of an acceptance rate standard, and its failure
    to take into consideration factors relevant to the number of offers made and
    the work assignments the grievor ought reasonably to have accepted.

[72]

Second, the appellant argues that the prior
    arbitral jurisprudence rejects the consideration of any and all personal circumstances
    or subjective factors in assessing reasonable availability, and then contends
    that anything other than the mechanical application of the peer average would fall
    into this category of irrelevant factors.

[73]

The arbitral jurisprudence is not entirely
    consistent with respect to whether and in what circumstances an employees
    personal circumstances can be considered.

[74]

Many of the cases considered whether there had
    been a marked improvement in the employees rate of acceptance after a warning
    had been given. See, for example, the Sabourin Arbitration, at paras. 76.2,
    85.2, 88.3 and 91.2, endorsed by the Court of Appeal of Quebec, at para. 22.

[75]

This is clearly a circumstance that is
    routinely taken into consideration, although personal to the employee. Some cases
    state specifically that an employees reasons for refusing work cannot be considered
    (see the Sabourin Arbitration, at para. 59), while in other cases these reasons
    were considered (see the Second Lanyon Arbitration, at. paras. 94-96). And the Corporations
    own guidelines, referred to by the arbitrator in this case, suggest that employees
    have the opportunity to explain their unavailability before a termination takes
    place under Article 44.11(b).

[76]

The arbitrator in this case was invited to
    consider such factors as the grievors reasons for refusing particular shifts;
    however, he declined to review the evidence offer by offer. As such, the
    reasons Mr. Seivright refused work offers (his religious observance, family
    commitments and other work demands) did not play any determinative role in the
    arbitrators decision. It is unnecessary to consider whether and to what extent
    Mr. Seivrights reasons for not accepting work reasonably could have been
    considered. And it is similarly unnecessary for this court to determine whether
    and to what extent any reason for refusing work (other than the sanctioned
    reasons enumerated as exceptions in Article 44.11(b)) might have to be
    considered.

[77]

In any event, the 24/7 operation of the YDC, the
    heavy parcel volume, the single temporary employee list and Mr. Seivrights
    seniority are not personal circumstances or subjective considerations. Rather,
    they are circumstances relevant to how often work was offered, and that provide
    the necessary context for the determination of whether the grievor was
    reasonably available to accept work assignments.

3.

Was the Arbitrators Decision Otherwise Reasonable?

[78]

I begin with the arbitrators erroneous
    statement at para. 61, that
the
relevant consideration for determining
    a lack of reasonable availability pursuant to Article 44.11 is whether there
    was a failure to accept work assignments which resulted in mail delivery being
    impeded (emphasis added). I agree with the appellant, as did the Divisional
    Court, that it was unreasonable for the arbitrator to inject into the analysis
    a prerequisite of prejudice to the employer. As noted earlier, this is not
    supported by and appears inconsistent with both the plain language of Article
    44.11(b) and the arbitral jurisprudence.

[79]

However, the question for appellate review is
    whether the arbitrators consideration of the lack of prejudice to the
    Corporation rendered the result unreasonable. An
error in the arbitrator's analysis would not necessarily lead to an
    unreasonable decision. A reasonableness review is not an examination of the
    weakest link of a chain of analysis in isolation from the reasons as a
    whole:
Petro-Canada v. British Columbia (Workers' Compensation
    Board)
,
2009 BCCA 396
,
98 B.C.L.R. (4th) 1
, at para. 56. Nor is it a "line-by-line treasure
    hunt for error":
Communications, Energy and Paperworkers
    Union of Canada, Local 30 v. Irving Pulp & Paper, Ltd.
,
2013
    SCC 34
,
[2013] 2 S.C.R. 458
, at para. 54.
In effect, the
    majority of the Divisional Court concluded that this error (as well as the
    departure from an acceptance rate approach, which I have concluded was not an
    error) did not render the arbitrators decision unreasonable, while the
    minority opinion of Wilton-Siegel J. concluded that these errors did.

[80]

The point of departure, as the arbitrator noted,
    is that the collective agreement speaks of an employees obligation to
    demonstrate reasonable availability in the acceptance of work assignments. It
    does not define what is reasonable in numerical terms nor do the Corporations
    policies provide a formula or other method for determining reasonable
    availability. Instead, the guidelines instruct supervisors specifically not to
    action every refusal or attempted call and to evaluate each case for
    termination individually based on its merits. The policies further direct that consideration
    must be given to local practice and how temporary employee lists are structured,
    including that lists may cover a 24/7 period, in which case the expectation
    for availability may be lower.

[81]

As I have explained, the prior arbitral
    jurisprudence did not require the use of an acceptance rate as a proxy for
    reasonable availability. The arbitrator characterized the use of an acceptance rate
    in the circumstances as leading to unreasonable and absurd consequences, having
    regard to the number of shifts available to the grievor (because of the YDCs
    24/7 operation, high number of parcels and his seniority). It was open to the
    arbitrator to reach this conclusion.

[82]

There was nothing in Mr. Seivrights letter of
    hire, or for that matter in the warning letters he received, indicating that he
    was expected to accept 50% of all of the shifts that he was offered, or that
    indicated that his acceptance
rate
would be compared with the rate of
    other temporary employees. The requirement in the collective agreement, and what
    was communicated consistently, was that Mr. Seivright demonstrate reasonable
    availability in the acceptance of work assignments.

[83]

Because the termination of an employee for
    failure to demonstrate reasonable availability is not subject to discretion
    (for example, to apply progressive sanctions or to substitute an alternative
    disciplinary measure short of dismissal on arbitration), it is essential that
    the employers approach not be arbitrary or unjust. There is nothing
    unreasonable in the arbitrators rejection of the employers automatic approach
    in this case, or in his characterization of the Corporations use of an
    acceptance rate as arbitrary and unreasonable.

[84]

What is or is not reasonable availability
    must be determined in light of the relevant circumstances of each case. It is
    reasonable to consider the circumstances that underlie how often work is
    offered to the temporary employee. Considered in this way, the increased parcel
    volume at the YDC, its 24/7 operation, the placement of all temporary employees
    on a single call list, and Mr. Seivrights position on that list by virtue of
    seniority, were all relevant factors and properly considered by the arbitrator.
    Even a cursory review of these circumstances demonstrates that measuring Mr.
    Seivrights
rate
of acceptance against the average acceptance rate of
    all temporary employees at the YDC could not be used mechanically to determine
    whether he was reasonably available to accept work assignments.

[85]

Attempting to identify a reasonable acceptance
    rate in a case like this may well inject an unnecessary and impractical step
    into the analysis. Instead, as the arbitrator noted, reasonable availability
    could be determined by considering the actual hours worked by the grievor in
    the context of the frequency of calls that the grievor received. The
    expectation that the grievor would accept 50% (or whatever the peer average
    was) of work offers, when he could be offered shifts at any time of day, seven
    days a week, and where he ultimately received more work offers over the
    six-month period than it was possible to work,  was reasonably described by the
    arbitrator as absurd.

[86]

In my view, the arbitrators decision was
    reasonable. It was within the range of possible, acceptable outcomes for him to
    conclude that the grievor demonstrated reasonable availability in all the
    circumstances of the case. His reasons exhibit the qualities of justification,
    transparency and intelligibility required by the Supreme Court of Canada in
Dunsmuir
.

[87]

While the arbitrator erred in requiring proof of
    prejudice to the Corporation as a result of the grievers failure to accept
    shifts, this error did not drive the result. The substance of his decision consisted
    of explaining why he rejected the employers insistence on a mechanical formula
    to determine reasonable availability, and his view, which is consistent with
    the arbitral jurisprudence and the Corporations own policies, that reasonable
    availability must be determined on a case-by-case basis having regard to the
    relevant circumstances of the employment.

[88]

The arbitrator did not err in rejecting the
    Corporations use of an acceptance rate after concluding that the use of an
    acceptance rate to assess reasonable availability would negatively affect
    workers with higher seniority, as they would automatically receive more offers
    which would in turn dilute their acceptance rates and expose them to greater
    risk of termination. And he did not err in considering, as part of the relevant
    circumstances, the factors that were directly relevant to the amount of work
    that was available and the frequency with which Mr. Seivright would be called
    upon for work. He also did not err, in my view, in pointing out that, if Mr.
    Seivright had been required to accept 50% of the work he was offered, he would
    have had to work 3.5 shifts per week, which is roughly equivalent to part-time
    hours. It would be unreasonable to uphold the termination of a temporary
    employee who, in terms of hours worked, was the 17th highest, and in the top 25
    to 30% of all temporary employees at the YDC. It was reasonable to conclude
    that Mr. Seivright did not have to work the hours of a full-time or even
    part-time employee to demonstrate reasonable availability as a temporary
    employee.

[89]

The arbitrator noted that there was no corporate
    policy concerning the use of an acceptance rate at the time of implementation
    of the Eclipse system. And, as discussed, there is no requirement in the
    arbitral jurisprudence for an arbitrator to use or defer to such an approach.
    As the arbitrator pointed out in the present case, the Corporations reference
    to a 50% or a peer average acceptance rate does not assist in determining
    reasonable availability in a case like Mr. Seivrights.

CONCLUSION AND DISPOSITION

[90]

In the final analysis, the arbitration award was
    reasonable. The Corporations use of a mechanical standard based entirely on
    the average acceptance rate for temporary employees at the YDC during the
    relevant six-month period was not mandated by the prior arbitral jurisprudence.
    In the circumstances of this case, it also was an arbitrary approach that did
    not properly address whether the grievor was reasonably available to accept
    work assignments. While the arbitrator impermissibly injected into the analysis
    a pre-condition of corporate prejudice, this error did not drive the outcome.
    Rather, the arbitrator reasonably considered the number of offers made to the
    grievor; the shifts he actually worked, in the context of the 24/7 operation of
    the YDC; the use of a single call list ordered by seniority; and the higher
    parcel volume, which led to greater reliance on temporary employees and a much
    higher number of available shifts.

[91]

For these reasons, I would dismiss the appeal. I
    would award costs to the respondent fixed at $12,000, inclusive of disbursements
    and HST, the amount agreed between the parties.

Released: June 11, 2019 K.F.

K. van Rensburg J.A.

I agree. K. Feldman J.A.

I agree.
I.V.B. Nordheimer J.A.

[1]
According to the appellants counsel, the Eclipse system was in use in Montreal
    as early as 2006, but was extended nationally in 2014.

[2]
The prior arbitral jurisprudence consists of the following cases:
Syndicat
    des travailleurs et travailleuses des postes c. Société canadienne des postes
(August
    15, 2005),  Arbitration Decision No. 2005-32 (Arbitrator Rodrigue
Blouin
) (the Blouin Arbitration);
Canadian
    Union of Postal Workers v. Canada Post Corporation
(September 27, 2005) (Arbitrator
    Stan Lanyon) (the First Lanyon Arbitration);
Syndicat des travailleurs et
    travailleuses des postes c. Société canadienne des postes
, [2006] D.A.T.C.
    no. 281, 2006 CarswellNat 2321 (Arbitrator Diane
Sabourin
) (the Sabourin Arbitration), affd 2007 QCCS 4508,
    affd

2008 QCCA 1232;
Syndicat des travailleurs et travailleuses des
    postes c. Société canadienne des postes
, [2006] D.A.T.C. no. 302 (Arbitrator
    André Rousseau) (the Rousseau Arbitration), revd 2007 QCCS 4497, revd 2008
    QCCA 1232;
Canadian Union of Postal Workers v. Canada Post Corporation
(2006),
    156 L.A.C. (4th) 109 (Arbitrator Stan Lanyon) (the Second Lanyon Arbitration);
Canadian Union of Postal Workers v. Canada Post Corporation
(December 11, 2013),
    Arbitration Decision No. 2013-44 (Arbitrator Wayne Thistle) (the Thistle
    Arbitration). This court was provided with English translations for internal
    use of the Quebec arbitral and court decisions.

[3]
Although the Thistle Arbitration and the First and Second Lanyon Arbitrations concerned
    temporary employees on a single list, there is no indication that employees on
    such a list could be contacted at any hour of the day or night.