3 Months Non Usage

Hello all,

Thank you for your help.  I am trying to create a calculation that has been working in an MS Access Database up to now but has become REALLY SLOW!

I am visualizing cost and count of devices for my company's wireless program.  Part of the visualization is to identify devices that are not being used AKA "nonUsage"

NonUsage is defined as the a device that has no usage (voice, text, data) for the last three months.

Example:

Device 123 in Jan was 0

Device 123 in Feb was 0

Device 123 in Mar was 0

Therefore in Mar Dev 123 is considered "nonUsage"

I have created two calcs to do this that are based upon the Max Month in the dataset.

My calcs are:

Calc 1: IF [Month]>=DATEADD('month',-2,{max([Month])}) then [Usage] END

Calc 2:

IF {FIXED [Device ID],[Phone Number],[Month]:sum([!Non-Usage Calc (1)])} = 0 THEN "nonUsage"

else "In Use"

END

If I filter my viz to just show the "nonUsage" values this works.

What I am looking to do now are two things:

1. Improve what I already have

2. Modify this logic so that for any month, the logic looks back at the previous two month and sums the usage with the current month.

I have attached a sample dataset.

Months where nonUsage should be found:

Dog in Oct 2019

Cat in Dec 2019

Months where nonUsage should not be found:

Zebra in Nov 2019 becuase there was only 2 months of nonUsage.

I am working in 2018.1

Thank you,

Scott