Can i use analysis groups as a method of contribution analysis?

Question

Hi.

I'm trying to use analysis groups in openLCA to perform contribution analysis for our EPDs, where I want to see the impact contribution from different life cycle stages like A2: Truck transport and A2: Ship transport. 

However, I'm encountering problems when adding multiple analysis groups to my product system. I'm experiencing one of two issues:

1. openLCA runs out of memory during calculation
2. All analysis groups show zero results across all impact categories

The analysis groups work fine individually or in smaller numbers, but the problems occur when I add many groups to cover all the processes I need to analyze.

Questions:

• Is there a recommended limit for the number of analysis groups that can be used effectively in a single product system?
• Could this be a configuration issue on my part, or is this a known software limitation?
• Are there any best practices for organizing analysis groups when dealing with complex EPD calculations?

Any insights or workarounds would be greatly appreciated!

Answer 1

Hi, good question, the analysis groups work fast if you have a quite simple, tree-like model without loops. They work also otherwise, but the calculation becomes quite tricky and thus takes time and memory. Of course you can check the available memory and expand if possible.

Comments

Hi Andreas,

Thanks for your reply.

Following up on that, I've observed a potential limit with analysis groups. When I exceed 15 groups in my product system, I get an empty result set, but it works correctly with 15 or fewer.

Could you clarify if this is a built-in software limitation or more likely a memory issue?

Thanks,
Sebastian

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Hi Sebastian, this is not a built-in software limitation. All the best, Andreas