Calculating time between steps

[SteveCampbell]

Hi,

I have been stuck on this now for a little and cannot seem to figure it out.

I have the following table:

item no	step a	step b	step c	step d
item 1	11/20/2016		11/29/2016
item 2		11/15/2016
item 3
item 4
item 5	11/1/2016	11/22/2016	11/28/2016
item 6	11/2/2016			11/29/2016
item 7
item 8		11/29/2016

What I'm trying to do is figure out how long the time difference is between steps. Not all steps are used for each item. My output could be something like this (but if there are better ways to output I don't mind):

item no	step a	step b	step c	step d
item 1			9
item 2
item 3
item 4		21	6
item 5				27
item 6
item 7
item 8

So for example, I could say on item 1 step C took 9 days since the last copmpleted step, which is enough detail. I'm struggling trying to find a solution, on how to arrange this in Power BI. Initially I've been trying along the lines of transpose and fill down, but this has not been working for me.

Thank you in advance for your help!

[ImkeF · Accepted solution]

Check this out:

    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WyixJzVUwVNJRMjLQNzTUNzIwNANyQHxLZH6sDlSpEUTW0BRVNUKBMVQATdgEu7ApkGdgiGSWkREyxwKrG0A8AyM0B6C4GK7UHLu1Ftj8CFIQCwA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type text) meta [Serialized.Text = true]) in type table [#"item no" = _t, #"step a" = _t, #"step b" = _t, #"step c" = _t, #"step d" = _t]),
    #"Unpivoted Other Columns" = Table.UnpivotOtherColumns(Source, {"item no"}, "Attribute", "Value"),
    #"Filtered Rows" = Table.SelectRows(#"Unpivoted Other Columns", each ([Value] <> "")),
    #"Changed Type" = Table.TransformColumnTypes(#"Filtered Rows",{{"Value", type date}}),
    AddIndex = Table.AddIndexColumn(#"Changed Type", "Index", 0, 1),
    #"Added Custom" = Table.AddColumn(AddIndex, "Duration", each if [Index]>0 and [item no]=AddIndex[item no]{[Index]-1} then Number.From([Value])-Number.From(AddIndex[Value]{[Index]-1}) else "" ),
    #"Removed Columns" = Table.RemoveColumns(#"Added Custom",{"Index", "Value"}),
    #"Pivoted Column" = Table.Pivot(#"Removed Columns", List.Distinct(#"Removed Columns"[Attribute]), "Attribute", "Duration")
in
    #"Pivoted Column"

If you also need the empty item numbers, just let me know.

[SteveCampbell]

You are awesome - that works perfectly! I've just started learnign DAX / Power Query so walking through your steps really helps me unsderstand the logic.

Thanks a lot!