help with vlookup, offset or match formula's
 

Hello,

I have a simplified spreadsheet pasted below. I am trying to calculate the
delta of a number (meter) between identical serial number machines (sn) and a
part that was used. The trick is that some parts are part of a kit, so I
need to determine delta of meter between like parts and kits that include the
part. I will have a table that will show that part "2" is included in part
"6".

sn part Date meter countif delta meter answer should be€¦
a 2 01/01/08 10 5 10
a 2 02/01/08 150 5 140
a 5 03/01/08 200 5 200
a 6 04/01/08 300 5 290
a 1 05/01/08 400 5 400
b 6 07/01/08 225 2 225
b 2 08/01/08 250 2 25
c 1 09/01/08 25 1 25






outcomes:
delta of meter between like parts
delta of meter between parts that are part of kits

table
part no. kit
2 6