How to design an on-going line chart that updates whenever the query is refreshed

[M_Potts]

I am trying to create a line graph that logs data whenever the user refreshes the query. The purpose is for different units of business (e.g. managers who handle customers in rome verses greece etc) to be able to compare their increasing quality of data. Filtering out business unit is very easy, but actually capturing the backlog of data, saving it then plotting it as the 'previous' point in the graph seems extremely difficult. 

For example, if an area manager with the data quality dashboard 'refreshes' the query, he should be able to see today's count of incorrect customers, but any previous values remain plotted on the graph. 

Then, after say 12 months, I would want to remove the oldest reading so that the graph doesn't get too long.

I have included an image to show the type of thing I want to do - I have just used bad naming and a couple of countries as random examples: 

[v-shex-msft]

HI @M_Potts,

>>For example, if an area manager with the data quality dashboard 'refreshes' the query, he should be able to see today's count of incorrect customers, but any previous values remain plotted on the graph. 

Current power bi not support auto add analysis line to visual graphic when refresh operation.

For control x axis startpoint and endpoint, you can manually setting at format tab. 

I haven't found any features support to setting line value to zero at specific point, I'd like to suggest you use measure to replace the value column and add condition to replace specific value to 0.

Sample:

Measure =
IF (
    DATEDIFF ( TODAY (), MAX ( MAX ( date ), TODAY () ), MONTH ) > 12,
    0,
    SUM ( table[amount] )
)

Regards,

Xiaoxin Sheng