On the Control Flow canvas add a Script Task and connect that to the Data Flow task.

In the following example the Script Task loops until the file becomes available or a timeout period has expired.

' VB.Net

' Returns success if file can be opened before a timeout period has expired

' Note: Add Imports System.IO at beginning

'

' Replace hardcoded file name with package variable.

Dim strFilename As String = "c:\temp\input.csv"

Dim fsMyFile As System.IO.FileStream

Dim bFinished As Boolean = False

Dim iCount As Integer = 1

dim iTimeout as Integer = 60

Do

Try

fsMyFile = System.IO.File.Open(strFilename,FileMode.Open,FileAccess.ReadWrite,FileShare.None)

bFinished = True

fsMyFile.Close()

Catch ioex As System.IO.IOException

iCount += 1

System.Threading.Thread.Sleep(1000)

End Try

Loop Until bFinished Or iCount > iTimeOut

If bFinished Then

Dts.TaskResult = Dts.Results.Success

Else

Dts.TaskResult = Dts.Results.Failure

End If