Hi Aman,
it would really help if you could share at least some other DMN, with a _similar_ table as the one contained in [model_name_here].
I can understand your original DMN model is confidential and you don't have a Red Hat subscription to share confidentially your actual DMN model.
If you are able however to build a synthetic, similar, "example" DMN model, which also takes the same long time to build your kjar, we can take a look into that instead, to try to investigate the real root cause.
Let us know :)
At the same time, you can use this configuration to skip DT analysis while performing your KJAR build:
Hope this helps!
MM