function Start-ServicesByTier {
<#
.SYNOPSIS
    Starts all services that fall under the Tier parameter

.PARAMETER Tier
    Number specifing the tier of services

.PARAMETER IncludeLowerTiers
    Also include services from all tiers lower than the provided tier.
    (With this switch present, -Tier 0 starts only tier 0 service names, 1 starts both tier 0 and 1 services, 2 starts
    tier 2, 1, and 0, ad infinitum.) Values provided above the number of defined tiers simply start all available tiered services.
#>
    [CmdletBinding()]
    param(
        [Parameter(Mandatory = $true)]
        [ValidateRange(0, [int]::MaxValue)]
        [int]$Tier,

        [Parameter(Mandatory = $false)]
        [switch]$IncludeLowerTiers
    )

    $hostname = $env:COMPUTERNAME
    $results = @{
        Hostname    = $hostname
        HasError    = $false
        ReturnValue = @()
    }

    $maxTier = $Tier
    if ($IncludeLowerTiers) {
        $minTier = 0
    } else {
        $minTier = $Tier
    }

    # Assigning $minTier to 0 if the $IncludeLowerTiers param is enabled, otherwise matching up the $min/$maxTier params to only iterate through one tier
    for ($i = $minTier; $i -le $maxTier; $i++) {
        # Because I want to make my conditionals more readable
        $isStartingTier0 = $i -eq 0
        $stoppedServicesInTier = @()
        try {
            $stoppedServicesInTier = @()
            $servicesByTier = (Get-ServicesByTier -Tier $i)
            foreach ($service in $servicesByTier) {
                $serviceStatus = (Get-Service $service -ErrorAction SilentlyContinue).Status -eq "Stopped"
                if ($serviceStatus) {
                    $stoppedServicesInTier += $service
                }
            }
            $hasStoppedServicesInTier = -not (Test-IsCollectionNullOrEmpty -Collection $stoppedServicesInTier)
        } catch {
            Write-Warning $_
        } finally {
            if ($hasStoppedServicesInTier) {
                $startServicesResults += Start-ServicesInParallel -ServiceNamestoStart $stoppedServicesInTier -ReturnResults

                $results.ReturnValue = $startServicesResults
                $results.HasError = -not (Test-IsCollectionNullOrEmpty -Collection $results.ReturnValue)
            } else {
                Write-Host "All services in Tier $i were already running"
                $results.ReturnValue = @()
            }
        }
        if ($results.HasError -and $isStartingTier0) {
            # when Tier 0 (Subscription,Broker) fails to start, return results immediately so we can fail the job
            Write-Warning "Exceptions were thrown trying to start serivces in Tier $i"
            Write-Warning "Returning a list of Exceptions or ErrorRecords"
        }
        return $results
    }
}