Today I created a decision model in OpenRules that describes all calculations in details.Hopefully, if I didn’t make mistakes, it will clarify your concerns – see https://goo.gl/Pfqr1L. Looking forward to seeing your solution,

Jacob ]]>

It does not answer my second question though. The code shown there indeed indicates that for calculating the value you indeed take all the equities minus the debts and the loan amount. In step 3, I would expect a change of 52k – 200k = -148k. However, 125200-148k = -22800 which is not 48800 as mentioned.

]]>I plan to provide a solution for this challenge using our latest DMN implementation as time permits. Meanwhile, you may see how it was done years ago with basic Rules tables at http://openrules.com/loan_dynamics.htm. I believe it includes the calculation logic as well.

Jacob ]]>

What I do not understand is how you compute that Peter Johnston has a personal equity in the first step. He has a monthly income of 4000 and monthly debt of 2500. I somehow have to combine this to get to an equity of 25200 according to the OpenRules video. How is this calculation done?

Another question is how you get to an accumulated remaining of 48800 in step 3. With a new debt of 200k and equity of 52k I would expect a change of 52k – 200k = -148k. However, 125200-148k = -22800 which is not 48800 as mentioned. ]]>

These are points that make the challenge difficult:

– Countries exist with no summer or winter time

– Countries in the southern hemisphere have summer and winter time turned around

– Each country starts summer and winter time on different days

– The days on which summer and winter time start can be different each year, with only a announcement shortly before starting

– Countries sometimes have a time difference of 30 or 45 minutes

– There are countries that are all year long on summer time, effectively escaping their timezone

All these points make me believe that calling a web service for this problem is the easiest solution, instead of modelling it myself, but what is the fun in that?

If it would only be about handling unknown/null values, it would have been easy.

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