■

　実装をちょい変更。
　実は、社員番号そのものが、結構な制約条件がついたりするけど。

Option Explicit On
Option Strict On

Public Class 社員

    Private _社員番号 As String

    Public Sub New()
        _社員番号 = 社員番号生成()
    End Sub

    Public Sub New(ByVal 社員番号 As String)
        _社員番号 = 社員番号
    End Sub

    Private _苗字 As String
    Public Property 苗字() As String
        Get
            Return _苗字
        End Get
        Set(ByVal value As String)
            _苗字 = value
        End Set
    End Property

    Private _名前 As String
    Public Property 名前() As String
        Get
            Return _名前
        End Get
        Set(ByVal value As String)
            _名前 = value
        End Set
    End Property

    Public Function 社員番号生成() As String
        Dim 返り値 As String = ""

        'ここで、DBアクセスとかして社員番号を取得してみる
        Return 返り値
    End Function

    Public Function 役職取得() As List(Of 役職)
        Dim 戻り値 As List(Of 役職) = New List(Of 役職)

        Return 戻り値
    End Function

End Class


Public Class 役職
    Public Sub New()

    End Sub

    Private _役職CD As String
    Public Property 役職CD() As String
        Get
            Return _役職CD
        End Get
        Set(ByVal value As String)
            _役職CD = value
        End Set
    End Property

    Private _役職名 As String
    Public Property 役職名() As String
        Get
            Return _役職名
        End Get
        Set(ByVal value As String)
            _役職名 = value
        End Set
    End Property

    Private _所属部署 As String
    Public Property 所属部署() As String
        Get
            Return _所属部署
        End Get
        Set(ByVal value As String)
            _所属部署 = value
        End Set
    End Property

End Class