Public Interface IWorkItemManager
    ''' <summary>
    ''' Fetches the work items for a certain work post.
    ''' </summary>
    ''' <param name="workPostIndex">The index of the work post, 0 based</param>
    ''' <returns>Collection of the work items</returns>
    Function GiveWorkItems(workPostIndex As Integer, employees As List(Of IEmployee)) As ICollection(Of IWorkItem)

    Sub StartActivity(activity As IActivity, employee As IEmployee)

    Sub FinishActivity(activity As IActivity)

    Sub StopActivity(activity As IActivity)

    Sub PauseActivities()

End Interface