Strange Ideal Trend Line in burndown chart

Question

I am getting a very strange idealtrend line in my burn down chart. The project has 400 hours of work in it, but the ideal trend starts at 100 hours. THis places 300 hours above the ideal trend, which looks very weird.
I would like to understand how the beginning point of the ideal trend line is calculated, perhaps this will help me figure out what is going on.
any help would be appreciated.

Answer 1

Hi,
You can
download the Agile Process Template to your local machine , and in the Reports folder, you can find the Burndown - Dashboard.rdl.  You can open this file using SQL Server Business Intelligence Development Studio or just notepad.exe.
In the rdl file, The IdealTrend Series is calculated as
=IIF (Parameters!TrendLineParam.Value = "both" OR Parameters!TrendLineParam.Value = "ideal",
Code.Burndown
IIF
( Parameters!YAxis.Value = "hours",
Sum(Fields!Cumulative_Remaining_Work.Value),
Sum(IIF(Fields!System_State.Value<>Parameters!ClosedName.Value, Fields!Cumulative_Count.Value, 0))
Fields!DateValue.Value,
Parameters!EndDateParam.Value
Nothing
 And Code.Burndown is defined as
Private firstValue As Double = Double.NaN
Private firstDate As Date
Private lastState As String
Private numDays As Integer
Function Burndown(ByVal val As Object, ByVal valDate As Date, ByVal endDate As Date)
If valDate &lt; firstDate Then
firstValue = Double.NaN
firstDate = DateTime.MinValue
End If
If Double.IsNaN(firstValue) Then
If Not val Is Nothing And val &lt;&gt; 0 Then
firstValue = val
firstDate = valDate
numDays = Math.Max(1, (endDate - valDate).Days)
Return firstValue
End If
Else
Return ((endDate - valDate).Days / numDays) * firstValue
End If
Return Nothing
End Function
From the Burndown function, when firstValue is NaN, the value is set to the parameter
val, and the series pass Sum(Fields!Cumulative_Remaining_Work.Value) as the parameter
val, so the beginning point of the ideal trend line is calculated as Sum(Fields!Cumulative_Remaining_Work.Value)
Best regards,
Ruiz
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