Extracting the results of access reviews in Entra ID

# Connect to the Microsoft Graph with the required scopes
Connect-MgGraph -Scope "AccessReview.Read.All"

# Get all access review defintions
Write-Host "Getting access review definitions"
$Definitions = Get-MgIdentityGovernanceAccessReviewDefinition -All -PageSize 100 -Verbose

# Filter to only those we care about
# $Definitions = $Definitions | Where-Object {$_.Scope.AdditionalProperties.query -like "*accessPackageAssignments*"}
$Definitions = $Definitions | Where-Object { $_.DisplayName -like "Teams review" }

# For each definition, get the latest completed instance
$Report = foreach ($Definition in $Definitions) {
    # Use to step through: $Definition = $Definitions | get-random -count 1
    Write-Host "Processing $($Definition.Status) AR: $($Definition.DisplayName) ($($Definition.Id))"
    $Instances = Get-MgIdentityGovernanceAccessReviewDefinitionInstance -AccessReviewScheduleDefinitionId $Definition.id -All
    $Instance = $Instances | Where-Object Status -in @("Completed") | Sort-object EndDateTime -Descending | Select-Object -First 1

    if (!$Instance) {
        Write-Warning "No active or completed instances found for $($Definition.DisplayName) ($($Definition.Id))    "
    }
    else {
        # Get all decisions for the instance
        $Decisions = Get-MgIdentityGovernanceAccessReviewDefinitionInstanceDecision -AccessReviewInstanceId $Instance.Id -AccessReviewScheduleDefinitionId $Definition.id -All

        # Process each decision, outputting a custom object for each
        foreach ($Decision in $Decisions) {
            # Use to step through: $Decision = $Decisions | get-random -count 1
            [PSCustomObject] @{
                Definition_DisplayName                = $Definition.DisplayName
                Definition_DescriptionForReviewers    = $Definition.DescriptionForReviewers
                Definition_Status                     = $Definition.Status
                Decision_Principal_DisplayName        = $Decision.Principal.DisplayName
                Decision_Principal_Id                 = $Decision.Principal.Id
                Decision_Principal_UserPrincipalName  = $Decision.Principal.userPrincipalName ?? $Decision.Principal.AdditionalProperties.userPrincipalName
                Decision_Decision                     = $Decision.Decision
                Decision_Recommendation               = $Decision.Recommendation
                Decision_Resource_DisplayName         = $Decision.Resource.DisplayName
                Decision_Resource_Id                  = $Decision.Resource.Id
                Decision_Resource_Type                = $Decision.Resource.Type
                Decision_ReviewedBy_DisplayName       = $Decision.ReviewedBy.DisplayName
                Decision_ReviewedBy_Id                = $Decision.ReviewedBy.Id
                Decision_ReviewedBy_UserPrincipalName = $Decision.ReviewedBy.UserPrincipalName ?? $Decision.ReviewedBy.AdditionalProperties.userPrincipalName
                Instance_Id                           = $Instance.Id
                Instance_StartDateTime                = $Instance.StartDateTime
                Instance_EndDateTime                  = $Instance.EndDateTime
                Decision_ApplyResult                  = $Decision.ApplyResult
            }
        }
    }
}

# To use Export-Excel, run this first: Install-Module ImportExcel -Scope CurrentUser
$Report | Export-Excel -Path ".\AccessReviewReport.xlsx" -AutoSize -AutoFilter -WorksheetName "AccessReviews" -TableName "AccessReviews" -Show -ClearSheet