Hi @Bhaskar ,
Sorry for slow response - I have been out of office for a few weeks.
Purely from the graph above the result of 14 months seems like a reasonable conclusion.
Clearly there is a lot of variation between your batches. And this is reflected in the fact that the stability protocol has determined that the different intercepts and different slopes is the most appropriate model.
The batch coloured in blue shows a strong downward trend in Disso, which suggests that it would be less than 85 from around 14 months.
The other batches show less clear trends. I can't comment on why that is. That is something for you to think about. It might be that the precision of Disso measurement is poor. You might want to look at the Disso measurement system using Measurement Systems Analysis methods (a topic for another thread). It might also be that there truly are differences in how the product in different batches is degrading.
You ask about statistical significance. The Stability platform uses statistical testing to determine the best model according to the ICH guidelines. Then, for the model that has been determined, it gives you the 95% confidence intervals for the trend, which is effectively another test of statistical significance.
The statistical tests are detailed in the help documentation.
I hope this helps.