Average leadtime between two max date

[guillaume_gorli]

Hello everyone,

I am working with a database listing ID Ticket, Category of ticket, Working Date and Closing Date as below : 

ID Ticket	Categorie	Working Date	Date
1	A	01-janv	11-janv
1	A	02-janv	11-janv
1	A	03-janv	11-janv
1	A	03-janv	11-janv
2	B	12-févr	17-févr
2	B	12-févr	17-févr
2	B	17-févr	17-févr
3	A	01-févr	15-févr
4	C	03-mars	06-mars
4	C	03-mars	06-mars
4	C	04-mars	06-mars
4	C	05-mars	06-mars
4	C	06-mars	06-mars
5	A	07-mars	08-mars
5	A	07-mars	08-mars
6	A	07-mars	17-avr
6	A	09-mars	17-avr
6	A	10-avr	17-avr
6	A	11-avr	17-avr
7	B	18-avr	19-avr
7	B	19-avr	19-avr
8	A	25-avr	05-juin
8	A	25-avr	05-juin
8	A	26-avr	05-juin
9	B	07-juin	08-juin
9	B	07-juin	08-juin
10	C	19-juin	22-juin

Thus, i have several working Date for the same ticket and one sole closing Date for each ticket.

What i am trying to do is determine a leadtime between last working Date and Closing Date. i Managed to get the leadtime per ticket  properly :

but now i need to produce a less detailed KPI showing average leadtime per category of ticket and per month but i cannot make it works.

This should look like this :

Mois	A	B	C	Average Leadtime
JAN	8,0			8,0
FEB	14,0	0,0		7,0
MAR	1,0		0,0	0,5
APR	6,0	0,0		3,0
MAY
JUN	40,0	1,0	3,0	14,7
Average Leadtime	13,8	0,3	1,5	7,3

Attached is qvw and excel database for those who could help.

Thanks in advance

Guillaume