Total SUM of story points per month based on state

[Anonymous]

Hi, 

I'm new to Power BI/DAX and I'm struggling to create a visualisation. 

What I would like to have is a stacked column chart which displays the total SUM of story points per month based on the state of the ticket in that period.

The totals for all states apart from "Resolved" should rollover to the next month unless the state changes.  

Example data

Transactions Table

ID	Created Date	OldState	NewState	ExitDate
TEST01	01/01/2019	Created	New	02/02/2019
TEST01	02/02/2019	New	Backlog	01/03/2019
TEST01	01/03/2019	Backlog	Resolved	NULL
TEST02	01/01/2019	Created	New	01/03/2019
TEST02	01/03/2019	New	Backlog	NULL
TEST03	01/02/2019	Created	New	NULL
TEST04	01/02/2019	Created	New	20/02/2019
TEST04	20/02/2019	New	Backlog	NULL
TEST05	01/03/2019	Created	New	NULL
TEST06	01/03/2019	Created	New	20/03/2019
TEST06	20/03/2019	New	Backlog	NULL
TEST07	05/03/2019	Created	New	25/03/2019
TEST07	25/03/2019	New	Backlog	01/04/2019
TEST07	01/04/2019	Backlog	Resolved	NULL

TicketList Table

ID	Created Date	Resolved Date	Current State	Story Points
TEST01	01/01/2019	01/03/2019	Resolved	5
TEST02	01/01/2019	NULL	Backlog	2
TEST03	01/02/2019	NULL	New	3
TEST04	01/02/2019	NULL	Backlog	5
TEST05	01/03/2019	NULL	New	9
TEST06	01/03/2019	NULL	Backlog	1
TEST07	05/03/2019	01/04/2019	Resolved	4

Manually Constructed Pivot

	New	Backlog	Resolved
Jan19	7	0	0
Feb19	2	10	0
Mar19	12	12	5
Apr19	12	8	4

I'm really sure where to start with this issue, any advice would be appreciated.

Many Thanks, 

Daniel

[Anonymous]

Using the following calculated column I have been able to calculate the correct values when in the ticket is in the "Resolved" state however I can't figure out how to carry over the values from the previous months when in other states. 

TEST = IF( 
        ISBLANK(Transactions[ExitDate]) && Transactions[NewState] == "Resolved", CALCULATE(SUM(TicketList[Story Points])), 
        CALCULATE(SUM(TicketList[Story Points])
))