How to calculate the number of people waiting in a queue

[ricardobresolin]

Dear Power BI community,

I have the following problem and I can not find my way out... 

For each sequence number, I have the number of people that enter the system and the number of people that the system has the capacity to process (output), so if input<output then the queue is ZERO, else the amount of the queue will be Queue(n-1) + Input - Output, as the print shows below. 

I need to replicate this excel calculation in a DAX function to calculate the number of people waiting in the queue. 

Any idea if it is feasible and how to proceed?

Many thanks in advance for your help

[Anonymous · Accepted solution]

Hi

I think there is a simple w<ay to write it but I did not find it.

Anyway, first I added a column to your table. Input-Output

Queue2 =

if(Feuil3[Input]>Feuil3[Ouput],Feuil3[Input]-Feuil3[Ouput],0)

and after I wrote this measure

queue =

VAR activseq =

    SELECTEDVALUE ( Feuil3[Sequence] )

VAR prevseq = activseq - 1

VAR preval =

    LOOKUPVALUE ( Feuil3[Queue2], Feuil3[Sequence], prevseq )

VAR calc =

    MAX ( Feuil3[Input] ) - MAX ( Feuil3[Ouput] )

VAR result =

    IF (

        SELECTEDVALUE ( Feuil3[Input] ) > SELECTEDVALUE ( Feuil3[Ouput] ),

        SELECTEDVALUE ( Feuil3[Input] ) + preval

            - SELECTEDVALUE ( Feuil3[Ouput] ),

        0

    )

RETURN

    result

Final result is this. I hope it helps.