topic Re: CUSUM vs EWMA for subgroup aggregate analysis in Discussions

CUSUM vs EWMA for subgroup aggregate analysis

RatioMegalodon8 — Tue, 12 Aug 2025 13:29:21 GMT

Hello, I would love help with this question. We created a process across 9 different divisions. All the Divisions entered the project at different times over 2 years. We have individual division control charts, but could a CUSUM or EWMA chart be used to display aggregate, discrete data across the whole system for subgroups that enter at different times? Thanks in advance for any help!

Re: CUSUM vs EWMA for subgroup aggregate analysis

Byron_JMP — Tue, 12 Aug 2025 14:01:48 GMT

What is it that you're trying to discover with CUSUM or EWMA?

Is you data aggregate or discrete? (X-bar or IR charts)

Re: CUSUM vs EWMA for subgroup aggregate analysis

RatioMegalodon8 — Tue, 12 Aug 2025 14:08:35 GMT

It is the aggregate of total numbers of numerators and denominators across all subgroups as they sequentially start the project.

This is simply for presentation purposes and not specifically for analysis which would reside at the individual division control chart level.

Thanks!

Re: CUSUM vs EWMA for subgroup aggregate analysis

Byron_JMP — Tue, 12 Aug 2025 14:24:31 GMT

What is it that you're trying to discover/visualize with CUSUM or EWMA?

Re: CUSUM vs EWMA for subgroup aggregate analysis

RatioMegalodon8 — Tue, 12 Aug 2025 14:32:38 GMT

The cumulative performance of all divisions as the process ‘spreads across the system’ acknowledging that as each division is added, they have the same change package as previous divisions but are distinct on their adaption and time to reach goal. We would be utilizing this just for higher level presentations to show staff how their cumulative work is so impressive, not analysis of the process itself which would reside with the individual divisions.

Re: CUSUM vs EWMA for subgroup aggregate analysis

Byron_JMP — Wed, 13 Aug 2025 13:07:20 GMT

It sounds like you want to plot the cumulative sum of X over time? Kind of like a forecast.

right click on your metric column, choose New Formula Column>Row>Cumulative Sum. This puts the cumulative sum formula in a new column