N层体系结构 – 在VB.NET中具有多个项目的结构

我将有一个Windows应用程序和一个Web应用程序(表示层),这些都将访问一个公共业务层.业务层将查看配置文件以查找将在运行时创建引用的dll(数据层)的名称(这是最好的方法吗？).

在运行时为数据访问层创建引用的原因是,应用程序将根据客户端使用的内容与不同的第三方记帐系统进行交互.所以我会有一个单独的数据访问层来支持每个会计系统.这些可能是单独的安装项目,每个客户端都会使用其中一个,他们不需要在两者之间切换.

项目：

MyCompany.Common.dll – 包含接口,所有其他项目都引用了这个接口.
MyCompany.Windows.dll – Windows窗体项目,引用MyCompany.Business.dll
MyCompany.Web.dll – 网站项目,引用MyCompany.Business.dll
MyCompany.Busniess.dll – 业务层,引用MyCompany.Data.*(在运行时)
MyCompany.Data.AccountingSys1.dll – 会计系统1的数据层
MyCompany.Data.AccountingSys2.dll – 会计系统2的数据层

项目MyCompany.Common.dll将包含所有接口,每个其他项目都会引用此接口.

Public Interface ICompany
    ReadOnly Property Id() as Integer
    Property Name() as String
    Sub Save()
End Interface

Public Interface ICompanyFactory
    Function CreateCompany() as ICompany
End Interface

项目MyCompany.Data.AccountingSys1.dll和MyCompany.Data.AccountingSys2.dll将包含如下所示的类：

Public Class Company
    Implements ICompany

    Protected _id As Integer
    Protected _name As String

    Public ReadOnly Property Id As Integer Implements MyCompany.Common.ICompany.Id
        Get
            Return _id
        End Get
    End Property

    Public Property Name As String Implements MyCompany.Common.ICompany.Name
        Get
            Return _name
        End Get
        Set(ByVal value as String)
            _name = value
        End Set
    End Property

    Public Sub Save() Implements MyCompany.Common.ICompany.Save
        Throw New NotImplementedException()
    End Sub

End Class

Public Class CompanyFactory
    Implements ICompanyFactory

    Public Function CreateCompany() As ICompany Implements MyCompany.Common.ICompanyFactory.CreateCompany
        Return New Company()
    End Function

End Class

项目MyCompany.Business.dll将提供业务规则并从数据层检索数据：

Public Class Companies

    Public Shared Function CreateCompany() As ICompany
        Dim factory as New MyCompany.Data.CompanyFactory
        Return factory.CreateCompany()
    End Function    

End Class

任何意见/建议将不胜感激.